Common Docker Operations and Commands

#include <iostream>
using namespace std;

const int N = 1e6 + 10;

int n;
int q[N];

void quick_sort(int q[],int l,int r)
{
    if(l>=r) return;
    int i = l-1;
    int j = r+1;
    int x = q[(l+r)/2];
    
    while(i<j){
        do i++; while(q[i]<x);
        do j--; while(q[j]>x);
        if(i<j) swap(q[i],q[j]);
    }
    
    quick_sort(q,l,j);
    quick_sort(q,j+1,r);
}


int main()
{
    scanf("%d",&n);
    for(int i=0;i<n;i++) scanf("%d",&q[i]);
    
    quick_sort(q,0,n-1);
    
    for(int i=0;i<n;i++) printf("%d ",q[i]);
    
    return 0;
}

#include<iostream>
using namespace std;

const int N = 1e6+10;
int n;
int q[N],tmp[N];

void merge_sort(int q[],int l,int r)
{
    if(l>=r)return;
    int mid = l+r >> 1;
    merge_sort(q,l,mid);
    merge_sort(q,mid+1,r);
    int k = 0;
    int i = l,j = mid+1;
    while(i<=mid && j<=r) {
        if (q[i]<=q[j]) tmp[k++] = q[i++];
        else tmp[k++] = q[j++];
    }
    while(i<=mid) tmp[k++] = q[i++];
    while(j<=r) tmp[k++] = q[j++];
    for(i=l,j=0;i<=r;i++,j++) q[i]=tmp[j];
}

int main()
{
    scanf("%d",&n);
    for(int i=0;i<n;i++) scanf("%d",&q[i]);
    
    merge_sort(q,0,n-1);
    
    for(int i=0;i<n;i++) printf("%d ",q[i]);
    
    return 0;
}

bool check(int x) {/* ... */} // 检查x是否满足某种性质

// 区间[l, r]被划分成[l, mid]和[mid + 1, r]时使用：
int bsearch_1(int l, int r)
{
    while (l < r)
    {
        int mid = l + r >> 1;
        if (check(mid)) r = mid;    // check()判断mid是否满足性质
        else l = mid + 1;
    }
    return l;
}
// 区间[l, r]被划分成[l, mid - 1]和[mid, r]时使用：
int bsearch_2(int l, int r)
{
    while (l < r)
    {
        int mid = l + r + 1 >> 1;
        if (check(mid)) l = mid;
        else r = mid - 1;
    }
    return l;
}

#include <iostream>
using namespace std;

const int N = 100010;
int arr[N];

int main()
{
    int n,q,k;
    scanf("%d%d",&n,&q);
    for(int i=0;i<n;i++) scanf("%d",&arr[i]);
    for(int i=0;i<q;i++) {
        scanf("%d",&k);
        int l=0,r=n-1;
        while(l<r)
        {
            int mid = l+r >> 1;
            if(arr[mid]>=k) r = mid;
            else l = mid+1;
        }
        if(arr[l]!=k) cout<<"-1 -1"<<endl;
        else{
            cout<<l<<" ";
            int l=0,r=n-1;
            while(l<r)
            {
                int mid = l+r+1 >> 1;
                if(arr[mid]<=k) l = mid;
                else r = mid-1;
            }
            cout<<r<<endl;
        }
    }
}

#include <iostream>
#include <algorithm>

using namespace std;

int main()
{
    double n;
    cin>>n;
    bool isNegtive = false;
    if(n<0) {
        isNegtive = true;
        n = n*-1.0;
    }
    double l=0,r=max(1.0,n);
    while((r-l)>1e-8)
    {
        double mid = (l+r)/2;
        if(mid*mid*mid>=n){
            r = mid;
        }
        else l = mid;
    }
    if(!isNegtive) printf("%lf\n",l);
    else printf("%lf\n",-1*l);
    
    return 0;
}

#include <iostream>
#include <vector>

using namespace std;

const int N = 1e6+10;

vector<int> add(vector<int>&A,vector<int>&B)
{
    vector<int> C;
    int t = 0;
    for (int i = 0; i<A.size()||i<B.size(); i ++ ){
        if(i<A.size()) t+=A[i];
        if(i<B.size()) t+=B[i];
        C.push_back(t%10);
        t/=10;//上一位的进位
    }
    if(t) C.push_back(1);
    return C;
}

int main()
{
    string a,b;
    vector<int> A,B;
    
    cin>>a>>b;
    for(int i = a.size()-1;i>=0;i--){
        A.push_back(a[i]-'0');
    }
    for(int i = b.size()-1;i>=0;i--){
        B.push_back(b[i]-'0');
    }
    
    auto C = add(A,B);
    
    for(int i = C.size()-1;i>=0;i--){
        printf("%d",C[i]);
    }
    return 0;
}

#include <iostream>
#include <vector>

using namespace std;

bool cmp(vector<int>&A,vector<int>&B){
    if(A.size()!=B.size()) return A.size()>B.size();
    else {
        for(int i=A.size()-1;i>=0;i--){
            if(A[i]!=B[i]) return A[i]>B[i];
        }
    }
    return true;
}

vector<int> sub(vector<int>&A,vector<int>&B)
{
    //要求——A>=B
    //if A>=B 直接计算A-B
    //else 计算-(B-A)
    
    vector<int> C;
    int t = 0;
    for (int i = 0; i<A.size(); i ++ ){
        t = A[i] - t;
        if(i<B.size()) t -= B[i];
        C.push_back((t+10)%10);
        if(t<0) t = 1;
        else t = 0;
    }
    while(C.size()>1 && C.back()==0) C.pop_back();
    return C;
}

int main()
{
    string a,b;
    vector<int> A,B;
    
    cin>>a>>b;
    for(int i = a.size()-1;i>=0;i--){
        A.push_back(a[i]-'0');
    }
    for(int i = b.size()-1;i>=0;i--){
        B.push_back(b[i]-'0');
    }
    if(cmp(A,B)){
        auto C = sub(A,B);
        for(int i = C.size()-1;i>=0;i--){
            printf("%d",C[i]);
        }
    }
    else{
        auto C = sub(B,A);
        printf("-");
        for(int i = C.size()-1;i>=0;i--){
            printf("%d",C[i]);
        }
    }
    
    return 0;
}

#include <iostream>
#include <vector>

using namespace std;

vector<int> mul(vector<int> A , int b)
{
    vector<int> C;
    int t = 0;
    for(int i=0;i < A.size() || t ; i++){
        if(i<A.size()){
            t += A[i] * b;
        }
        C.push_back(t % 10);
        t /= 10;
        // C.push_back((A[i] * b + t) % 10);
        // t = (A[i] * b + t) / 10;
    }
    while(C.size()>1 && C.back()==0) C.pop_back();
  	// 去除前导0
    return C;
}

int main()
{
    string a;
    int b;
    vector<int> A;
    cin>>a>>b;
    for(int i = a.size()-1;i>=0;i--){
        A.push_back(a[i]-'0');
    }
    
    auto C = mul(A,b);
    
    for(int i = C.size()-1;i>=0;i--){
            printf("%d",C[i]);
        }
}

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

vector<int> div(vector<int> &A, int b ,int &r){
    vector<int> C;// 商
    r = 0;// 余数
    // 从最高位开始算--不同于其他几种计算
    for(int i = A.size() - 1;i >= 0 ; i--){
        r = r * 10 + A[i];
        C.push_back(r / b);
        r %= b;
    }
    
    reverse(C.begin() ,C.end());
    
    while(C.size()>1 && C.back()==0) C.pop_back();
  	// 去除前导0
    return C;
}

int main()
{
    string a;
    int b;
    vector<int> A;
    cin>>a>>b;
    for(int i = a.size()-1;i>=0;i--){
        A.push_back(a[i]-'0');
    }
    
    int r;
    auto C = div(A,b,r);
    
    for(int i = C.size()-1;i>=0;i--){
        printf("%d",C[i]);
    }
    cout<<endl;
    cout<<r<<endl;
}

#include <iostream>
using namespace std;

const int N = 100010;
int a[N],S[N];

int main()
{
    int n,m;
    scanf("%d%d", &n, &m);
    
    for (int i = 1;i<=n;i++) scanf("%d", &a[i]);
    
    S[0] = 0;
    for(int i = 1;i<=n;i++){
        S[i] = S[i-1] + a[i];
    }
    for (int i = 0;i < m;i++){
        int l,r;
        scanf("%d%d", &l, &r);
        printf("%d\n",S[r]-S[l-1]);
    }
    
    return 0;
    
}

#include <iostream>
#include <cstring>
#include <algorithm>

const int N = 1010;
int a[N][N],S[N][N];

int main()
{
    int n,m,q;
    scanf("%d%d%d", &n, &m, &q);
    for (int i = 1; i <= n; i++){
        for (int j = 1; j <= m; j++){
            scanf("%d",&a[i][j]);
        }
    }
    S[0][0] = 0;
    for (int i = 1; i <= n; i++){
        for (int j = 1; j <= m; j++){
            S[i][j] =a[i][j] + S[i][j-1] + S[i-1][j] - S[i-1][j-1];
        }
    }
    
    int x1,x2,y1,y2;
    while(q--){
        scanf("%d%d%d%d", &x1, &y1 , &x2, &y2);
        int ans = S[x2][y2] - S[x1-1][y2] - S[x2][y1-1] + S[x1-1][y1-1];
        printf("%d\n",ans);
    }
    
    return 0;
}

#include <iostream>
#include <cstring>
#include <algorithm>

using namespace std;

const int N = 100010;
int a[N],b[N];

void op(int l,int r,int c){
    b[l] += c;
    b[r+1] -= c;
}

int main()
{
    int n,m;
    scanf("%d%d", &n, &m);
    for(int i=1;i<=n;i++){
        scanf("%d", &a[i]);
    }
    for(int i=1;i<=n;i++){
        op(i,i,a[i]);
    }
    
    /*接下来输入 m个操作，
    * 每个操作包含三个整数 l,r,c
    * 表示将序列中 [l,r]之间的每个数加上 c
    */
    while (m--) {
        int l,r,c;
        scanf("%d%d%d", &l, &r, &c);
        op(l,r,c);
    }
    
    for (int i = 1; i <= n; i++){
        b[i] += b[i-1];
    }
    for (int i = 1; i <= n; i++){
        printf("%d ",b[i]);
    }
    
    return 0;
    
    
}

#include <iostream>
#include <cstring>
#include <algorithm>

const int N = 1010;
int a[N][N],b[N][N];

void op(int x1,int x2,int y1,int y2,int c){
    b[x1][y1] += c;
    b[x2+1][y1] -= c;
    b[x1][y2+1] -= c;
    b[x2+1][y2+1] += c;
}

int main()
{
    int n,m,q;
    scanf("%d%d%d", &n, &m, &q);
    
    for (int i = 1; i <= n; i++){
        for (int j = 1; j <= m; j++){
            scanf("%d",&a[i][j]);
        }
    }
    for (int i = 1; i <= n; i++){
        for (int j = 1; j <= m; j++){
            op(i,i,j,j,a[i][j]);
        }
    }
    
    int x1,x2,y1,y2,c;
    while(q--){
        scanf("%d%d%d%d%d", &x1, &y1 , &x2, &y2, &c);
        op(x1,x2,y1,y2,c);
    }
    
    for (int i = 1; i <= n; i++){
        for (int j = 1; j <= m; j++){
            b[i][j] = b[i][j] + b[i][j-1] + b[i-1][j] - b[i-1][j-1];
        }
    }
    
    for (int i = 1; i <= n; i++){
        for (int j = 1; j <= m; j++){
            printf("%d ",b[i][j]);
        }
        puts("");
    }
    
    
    return 0;
}

#include <iostream>
#include <cstring>
#include <algorithm>


using namespace std;

const int N = 1e5 + 10;
int n;
int a[N],s[N];


int main()
{
    scanf("%d", &n);
    for(int i = 0;i < n;i++) {
        scanf("%d", &a[i]);
    }
    int maxLen = 0;
    for (int i = 0,j = 0; i < n; i++){
        s[a[i]]++;
        while(s[a[i]] > 1){
            s[a[j]]--;
            j++;
        }
        maxLen = max(maxLen,i - j + 1);
    }
    cout << maxLen;
    return 0;
}

#include <iostream>
#include <cstring>
#include <algorithm>

using namespace std;

const int N = 100010;

int n,m,x;
int A[N],B[N];


int main()
{
    scanf("%d%d%d", &n, &m, &x);
    for (int i = 0; i < n; i++) {
        scanf("%d", &A[i]);
    }
    for (int i = 0; i < m; i++) {
        scanf("%d", &B[i]);
    }
    int i, j;
    for(i = 0, j = m - 1; i < n; i++) {
        while (j >= 0 && A[i] + B[j] > x) j--;
        if(j >= 0 && A[i] + B[j] == x) {
            cout << i << ' ' << j;
            return 0;
        }
    }
    return 0;
}

int n = 10;
for(int k = 3;k >= 0;k--){
  cout << (n>>k & 1);
}

int x;
cout << (x & -x);

#include <iostream>
#include <cstring>
#include <algorithm>

using namespace std;

int lowbit(int x)  // 返回末尾的1
{
    return x & -x;
}

int main()
{
    int n;
    cin >> n;
    while (n--){
        int x;
        cin>>x;
        int res = 0;
        while(x){
            x -= lowbit(x);
            res++;
        }
        cout<<res<<' ';
    }
    return 0;
}

vector<int> alls; // 存储所有待离散化的值
sort(alls.begin(), alls.end()); // 将所有值排序
alls.erase(unique(alls.begin(), alls.end()), alls.end());   // 去掉重复元素

// 二分求出x对应的离散化的值
int find(int x) // 找到第一个大于等于x的位置
{
    int l = 0, r = alls.size() - 1;
    while (l < r)
    {
        int mid = l + r >> 1;
        if (alls[mid] >= x) r = mid;
        else l = mid + 1;
    }
    return r + 1; // 映射到1, 2, ...n
}

#include <iostream>
#include <cstring>
#include <algorithm>
#include <vector>

using namespace std;

typedef pair<int, int> PII;

const int N = 300010;
int n,m;
int a[N],s[N];

vector<int> alls;
vector<PII> add, query;

int find(int x)  // 二分
{
    int l = 0, r = alls.size() - 1;
    while(l<r){
        int mid = l+r >> 1;
        if(alls[mid] >= x){
            r = mid;
        }
        else{
            l = mid + 1;
        }
    }
    return r + 1;
}


int main()
{
    scanf("%d%d", &n, &m);
    while (n--) {
        int x,c;
        scanf("%d%d", &x, &c);
        add.push_back({x,c});
        
        alls.push_back(x);
    }
    while (m--) {
        int l,r;
        scanf("%d%d", &l, &r);
        query.push_back({l,r});
        alls.push_back(l);
        alls.push_back(r);
    }
    
    // 排序 & 去重
    sort(alls.begin(),alls.end());
    alls.erase(unique(alls.begin(), alls.end()),alls.end());
    // 处理插入
    for(auto item : add){
        int x = find(item.first);
        a[x] += item.second;
    }
    // 预处理前缀和
    for(int i = 1;i <= alls.size(); i++){
        s[i] = s[i-1] + a[i];
    }
    // 处理询问
    for(auto item : query){
        int l = find(item.first);
        int r = find(item.second);
        cout << s[r] - s[l-1] << endl;
    }
    return 0;
}

// 将所有存在交集的区间合并
void merge(vector<PII> &segs)
{
    vector<PII> res;

    sort(segs.begin(), segs.end());

    int st = -2e9, ed = -2e9;
    for (auto seg : segs)
        if (ed < seg.first)
        {
            if (st != -2e9) res.push_back({st, ed});
            st = seg.first, ed = seg.second;
        }
        else ed = max(ed, seg.second);

    if (st != -2e9) res.push_back({st, ed});

    segs = res;
}

#include <iostream>
#include <cstring>
#include <algorithm>
 
using namespace std;

const int N = 100010;
typedef pair<int,int> PII;

vector<PII> segs;

void merge(vector<PII> &segs){
    vector<PII> res;
    
    sort(segs.begin(),segs.end());
    
    int st = -2e9, ed = -2e9;
    for(auto seg : segs){
        if(ed < seg.first){
            if(st!= -2e9) res.push_back({st,ed});
            st = seg.first;
            ed = seg.second;
        }
        else ed = max(ed, seg.second);
    }
    if(st!= -2e9) res.push_back({st,ed});
    
    segs = res;
}

int main()
{
    int n;
    scanf("%d", &n);
    while (n--) {
        int l,r;
        scanf("%d%d", &l, &r);
        segs.push_back({l,r});
    }
    
    merge(segs);
    
    cout << segs.size() << endl;
  
    return 0;
    
}

#include <iostream>
#include <cstring>
#include <algorithm>

using namespace std;

const int N = 100010;

/* head存储链表头，
   e[i]存储节点i的值，
   ne[i]存储节点i的next指针，
   idx表示当前用到了哪个节点
 */
int head, e[N], ne[N];
int idx;

void init() // 初始化
{
    head = -1;
    idx = 0;
}

void insert_head(int x) // 插入头节点
{
    e[idx] = x;
    ne[idx] = head;
    head = idx;
    idx++;
}

void insert(int k, int x) // 在k坐标后插入节点(值为x)
{
    e[idx] = x;
    ne[idx] = ne[k];
    ne[k] = idx;
    idx++;
}

void remove_head() // 删除头节点head
{
    head = ne[head];
}

void remove(int k) // 删除下标k后的点
{
    ne[k] = ne[ne[k]];
}

int main()
{
    int M;
    scanf("%d", &M);
    init();
    while (M--) {
        int k, x;
        char op;
        
        cin >> op;
        if (op == 'H') {
            cin >> x;
            insert_head(x);
        }
        else if (op == 'D') {
            cin >> k;
            if (k == 0) {
                remove_head();
            }
            remove(k - 1);
        }
        else {
            cin >> k >> x;
            insert(k - 1,x);
        }
    }
    
    for(int i = head; i != -1; i = ne[i]){
        cout << e[i] << ' ';
    }
    cout << endl;
    
    return 0;
}

// e[]表示节点的值，l[]表示节点的左指针，r[]表示节点的右指针，idx表示当前用到了哪个节点
int e[N], l[N], r[N], idx;

// 初始化
void init()
{
    //0是左端点，1是右端点
    r[0] = 1, l[1] = 0;
    idx = 2;
}

// 在节点a的右边插入一个数x
void insert(int a, int x)
{
    e[idx] = x;
    l[idx] = a, r[idx] = r[a];
    l[r[a]] = idx, r[a] = idx ++ ;
}

// 删除节点a
void remove(int a)
{
    l[r[a]] = l[a];
    r[l[a]] = r[a];
}

#include <iostream>
#include <cstring>
#include <algorithm>

using namespace std;

const int N = 100010;
int m;
int e[N], l[N], r[N], idx;

//初始化 
//0号点:head pointer
//1号点:tail pointer
void init()
{
    r[0] = 1;
    l[1] = 0;
    idx = 2;
}

//在k号点右边边插入值为x的点
void insert_right(int k, int x)
{
    e[idx] = x;
    l[idx] = k;
    r[idx] = r[k];
    l[r[k]] = idx;
    r[k] = idx;
    idx++;
}

//在k号点左边插入值为x的点:直接实现
void insert_left(int k, int x)
{
    e[idx] = x;
    l[idx] = l[k];
    r[idx] = k;
    r[l[k]] = idx;
    l[k] = idx;
    idx++;
}

//在k号点左边插入值为x的点:调用法
void insert_left_call(int k, int x)
{
    insert_right(l[k], x);
}

//删除第k个点
void delete_k(int k)
{
    r[l[k]] = r[k];
    l[r[k]] = l[k];
}


int main()
{
    scanf("%d", &m);
    init();
    while (m--){
        string op;
        cin >> op;
        if(op == "L"){
            int x;
            cin >> x;
            insert_right(0, x);
        }
        else if(op == "R"){
            int x;
            cin >> x;
            insert_left(1, x);
        }
        else if(op == "D"){
            int k;
            cin >> k;
            delete_k(k + 1);
        }
        else if(op == "IL"){
            int k, x;
            cin >> k >> x;
            insert_left(k + 1, x);
        }
        else if(op == "IR"){
            int k, x;
            cin >> k >> x;
            insert_right(k + 1, x);
        }
    }
    
    for(int i = r[0]; i != 1; i = r[i]){
        cout << e[i] << " ";
    }
    cout << endl;
    
    return 0;
}

#include <iostream>
#include <cstring>
#include <algorithm>

using namespace std;

const int N = 100010;

int stk[N], tt;

int m;

void init()
{
    tt = 0;
}

void push(int x)
{
    stk[++tt] = x;
}

void pop()
{
    tt--;
}

bool isEmpty()
{
    if(tt > 0)
        return false;
    else 
        return true;
}

int query()
{
    return stk[tt];
}

int main()
{
    scanf("%d", &m);
    init();
    while(m--){
        string op;
        cin >> op;
        if(op == "push"){
            int x;
            cin >> x;
            push(x);
        }
        else if(op == "pop"){
            pop();
        }
        else if(op == "empty"){
            string e;
            e = isEmpty() ? "YES" : "NO";
            cout << e << endl;
        }
        else if(op == "query"){
            cout << query() << endl;
        }
    }
    return 0;
}

#include <iostream>
#include <cstring>
#include <algorithm>

using namespace std;

const int N = 100010;

int m;
int q[N], hh, tt;

void init(){
    tt = -1;
  	hh = 0;
}

void push(int x){
    q[++tt] = x;
}

void pop(){
    hh++;
}

bool isEmpty(){
    return hh <= tt ? false : true;
}

int query(){
    return q[hh];
}

int main()
{
    scanf("%d", &m);
    init();
    while(m--){
        string op;
        cin >> op;
        if(op == "push"){
            int x;
            cin >> x;
            push(x);
        }
        else if(op == "pop"){
            pop();
        }
        else if(op == "empty"){
            string e;
            e = isEmpty() ? "YES" : "NO";
            cout << e << endl;
        }
        else if(op == "query"){
            cout << query() << endl;
        }
    }
    return 0;
}

#include <iostream>

using namespace std;

const int N = 100010;

int n;
int stk[N], tt;

int main()
{
    scanf("%d", &n);
    while (n--){
        int x;
        cin >> x;
        while(tt && stk[tt] >= x) tt--;
        if(tt)
            // cout << stk[tt] << ' ';
            printf("%d ",stk[tt]);
        else
            // cout << -1 << ' ';
            printf("-1 ");
            
        stk[++tt] = x;
    }
}

#include <iostream>
#include <cstdio>

using namespace std;

const int N = 1000010;

int n, k;
int a[N], q[N], tt, hh;

int main()
{
    scanf("%d%d", &n, &k);
    
    for (int i = 0; i < n; i++) {
        scanf("%d", &a[i]);
    }
  	
  	//最小值
    hh = 0;
    tt = -1;
    for (int i = 0; i < n; i++) {
        
        // 判断队头是否已经滑出窗口
        if(hh <= tt && i - k + 1 > q[hh]){
            hh++;
        }
        while(hh <= tt && a[q[tt]] > a[i]){
            tt--;
        }
        q[++tt] = i;
        if(i >= k-1){
            printf("%d ", a[q[hh]]);
        }
    }
    printf("\n");
  	//最大值
    hh = 0;
    tt = -1;
    for (int i = 0; i < n; i++) {
        
        // 判断队头是否已经滑出窗口
        if(hh <= tt && i - k + 1 > q[hh]){
            hh++;
        }
        while(hh <= tt && a[q[tt]] <= a[i]){
            tt--;
        }
        q[++tt] = i;
        if(i >= k-1){
            printf("%d ", a[q[hh]]);
        }
    }
    return 0;
}

struct Material {
    sampler2D diffuse;
    vec3 specular;
    float shininess;
};

struct Light {
    vec3 position;
    vec3 direction;
    float cutOff;
    float outerCutOff;

    vec3 ambient;
    vec3 diffuse;
    vec3 specular;

    float constant;
    float linear;
    float quadratic;
};

void main()
{
    // ambient
    vec3 ambient = light.ambient * texture(material.diffuse, TexCoords).rgb;

    // diffuse
    vec3 norm = normalize(Normal);
    vec3 lightDir = normalize(light.position - FragPos);
    float diff = max(dot(norm, lightDir), 0.0);
    vec3 diffuse = light.diffuse * diff * texture(material.diffuse, TexCoords).rgb;

    // specular
    vec3 viewDir = normalize(viewPos - FragPos);
    vec3 reflectDir = reflect(-lightDir, norm);
    float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);
    vec3 specular = light.specular * (spec * material.specular);

    // spotlight (soft edges)
    float theta = dot(lightDir, normalize(-light.direction));
    float epsilon = (light.cutOff - light.outerCutOff);
    float intensity = clamp((theta - light.outerCutOff) / epsilon, 0.0, 1.0);
    diffuse  *= intensity;
    specular *= intensity;

    // attenuation
    float distance    = length(light.position - FragPos);
    float attenuation = 1.0 / (light.constant + light.linear * distance + light.quadratic * (distance * distance));
    ambient  *= attenuation;
    diffuse   *= attenuation;
    specular *= attenuation;

    vec3 result = ambient + diffuse + specular;
    FragColor = vec4(result, 1.0);
}