线段树入门版qwq
区间查询 区间修改（都是加法qaq）
1 #include<cstdio> 2 #include<iostream> 3 #define sz 100010 4 #define LL long long 5 using namespace std; 6 int n, m, x, y, pd, add = 0; 7 LL ans = 0; 8 struct seg { 9 LL l, r, w, f; 10 }tree[sz<<2]; 11 void build(int k, int left, int right) { 12 tree[k].l = left, tree[k].r = right; 13 if(left == right) { 14 scanf("%d",&tree[k].w); 15 return; 16 } 17 int mid = (tree[k].l + tree[k].r)>>1; 18 build(k<<1, left, mid), build(k<<1|1, mid+1, right); 19 tree[k].w = tree[k<<1].w + tree[k<<1|1].w; 20 } 21 int down(int k) { 22 tree[k<<1].f += tree[k].f; 23 tree[k<<1|1].f += tree[k].f; 24 tree[k<<1].w += tree[k].f*(tree[k<<1].r-tree[k<<1].l+1); 25 tree[k<<1|1].w += tree[k].f*(tree[k<<1|1].r-tree[k<<1|1].l+1); 26 // tree[k].w = tree[k<<1].w + tree[k<<1|1].w; emm 27 tree[k].f = 0; 28 } 29 void change(int k) { 30 if(x <= tree[k].l && y >= tree[k].r) { 31 tree[k].w += add*(tree[k].r-tree[k].l+1); 32 tree[k].f += add; 33 return;//emm 34 } 35 if(tree[k].f) down(k); 36 int mid = (tree[k].l+tree[k].r)>>1; 37 if(x <= mid) change(k<<1); 38 if(y > mid) change(k<<1|1); 39 tree[k].w = tree[k<<1].w + tree[k<<1|1].w; 40 } 41 void ask_sum(int k) { 42 if(x <= tree[k].l && y >= tree[k].r) { 43 ans += tree[k].w; 44 return; 45 } 46 if(tree[k].f) down(k); 47 int mid = (tree[k].l+tree[k].r)>>1; 48 if(x <= mid) ask_sum(k<<1); 49 if(y > mid) ask_sum(k<<1|1); 50 } 51 int main() { 52 scanf("%d%d",&n,&m); 53 build(1,1,n); 54 for(int i = 1; i <= m; i++) { 55 scanf("%d%d%d",&pd,&x,&y); 56 if(pd == 1) { 57 scanf("%d",&add); 58 change(1); 59 } 60 else { 61 ans = 0; 62 ask_sum(1); 63 printf("%lld ",ans); 64 } 65 } 66 }