线段树（结构体）模板

#include<iostream>
#include<cstdio>
#include<queue>
#include<cstring>
#include<algorithm>
#include<map>
#include<cmath>
#include<string>
using namespace std;
typedef long long ll;
int ans;
struct node
{int l, r, w;int f;
};
struct node tree[50000 * 4 + 1];
void BuildSegmentTree(int k, int l, int r)     // 建线段树
{tree[k].l = l;tree[k].r = r;if(l == r){scanf("%lld", &tree[k].w);return ;}int m = (tree[k].l + tree[k].r) >> 1;BuildSegmentTree(k << 1, l, m);BuildSegmentTree(k << 1 | 1, m + 1, r);tree[k].w = tree[k << 1].w + tree[k << 1 | 1].w;
}
void down(int k)                      // 懒标记
{tree[k << 1].f += tree[k].f;tree[k << 1 | 1].f += tree[k].f;tree[k << 1]. w += tree[k].f * (tree[k << 1].r - tree[k <<1].l + 1);tree[k << 1 |1].w += tree[k].f * (tree[k << 1| 1].r - tree[k << 1| 1].l + 1);tree[k].f = 0;
}
void Single_Point_Modification(int k, int x, int y)   // 单点修改
{if(tree[k].l == tree[k].r){tree[k].w += y;return ;}int m = (tree[k].l + tree[k].r) >> 1;if(x <= m) Single_Point_Modification(k << 1,x, y);else Single_Point_Modification(k << 1 | 1, x, y);tree[k].w = tree[k << 1].w + tree[k << 1 | 1]. w;
}
void Single_Point_Query(int k, int x)     // 单点查询
{if(tree[k].l == tree[k].r){ans = tree[k].w;return ;}if(tree[k].f) down(k);int m = (tree[k].l + tree[k].r) >> 1;if(x <= m) Single_Point_Query(k << 1, x);else Single_Point_Query(k << 1 | 1, x);
}
void Interval_modification(int k, int x, int y,int z)  //区间修改
{if(tree[k].l >= x && tree[k].r <= y){tree[k].w += (tree[k].r - tree[k].l + 1) * z;tree[k].f += z;return;}if(tree[k].f) down(k);int m = (tree[k].l + tree[k].r) >> 1;if(x <= m) Interval_modification(k << 1, x, y, z);if(y > m) Interval_modification(k << 1 | 1, x, y, z);tree[k].w = tree[k << 1].w + tree[k << 1 | 1].w;
}
void Interval_Query(int k, int x, int y)  //区间查询
{if(tree[k].l >= x && tree[k].r <= y){ans += tree[k].w;return ;}if(tree[k].f) down(k);int m = (tree[k].l + tree[k].r) / 2;if(x <= m) Interval_Query(k << 1, x, y);if(y > m) Interval_Query(k << 1 | 1, x, y);
}char s[10];
int main()
{int T, n;while(~scanf("%d",&T)){int cas = 0;while(T--){scanf("%d", &n);BuildSegmentTree(1,1,n);printf("Case %d:\n",++ cas);while(1){int x, y, z;getchar();scanf("%s",s);if(s[0] == 'E')break;else if(s[0]== 'A')  // 区间修改{scanf("%d %d %d", &x, &y, &z);Interval_modification(1,x,y,z);}else if(s[0] =='B')   // 区间查询{ans = 0;scanf("%d %d", &x, &y);Interval_Query(1, x, y);printf("%d\n",ans);}else if(s[0]=='C')  // 单点修改{scanf("%d %d", &x, &y);Single_Point_Modification(1,x,y);}else if(s[0]=='D')  // 单点查询{ans = 0;scanf("%d", &x);Single_Point_Query(1,x);printf("%d\n",ans);}}}}return 0;
}