poj3468 A Simple Problem with Integers（线段树区间更新）

https://vjudge.net/problem/POJ-3468

线段树区间更新（lazy数组）模板题

 #include<iostream>
 #include<cstdio>
 #include<queue>
 #include<cstring>
 #include<algorithm>
 #include<cmath>
 #include<map>
 #define lson l, m, rt<<1
 #define rson m+1, r, rt<<1|1
 #define INF 0x3f3f3f3f
 typedef long long ll;
 using namespace std;
 ll sum[<<], lazy[<<];
 void PushUP(int rt)
 {
     sum[rt] = sum[rt<<]+sum[rt<<|];
 }
 void PushDown(int rt, int m)
 {
     if(lazy[rt]){//若有标记下移
         lazy[rt<<] += lazy[rt];
         lazy[rt<<|] += lazy[rt];
         sum[rt<<] += (m-(m>>))*lazy[rt];
         sum[rt<<|] += (m>>)*lazy[rt];
         lazy[rt] = ;//取消本层标记
     }
 }
 void build(int l, int r, int rt)
 {
     lazy[rt] = ;//一定写在if外初始化
     if(l == r){
         scanf("%lld", &sum[rt]);
         return ;
     }
     int m = (l+r)>>;
     build(lson);
     build(rson);
     PushUP(rt);
 }
 ll Query(int L, int R, int l, int r, int rt)
 {
     if(L<=l&&R>=r){
         return sum[rt];
     }
     PushDown(rt, r-l+);//向下更新
     int m = (l+r)>>;
     ll ans=;
     if(L <= m) ans += Query(L, R, lson);
     if(R > m) ans += Query(L, R, rson);
     return ans;
 }
 void Update(int L, int R, ll add, int l, int r, int rt)
 {
     if(L<=l&&R>=r){
         sum[rt] += (r-l+)*add;
         lazy[rt] += add;
         return ;
     }
     PushDown(rt, r-l+);//向下而更新
     int m=(l+r)>>;
     if(L <= m) Update(L, R, add, lson);
     if(R > m) Update(L, R, add, rson);
     PushUP(rt);
 }
 int main()
 {
     int n, m, a, b;
     ll c;
     char op[];
     scanf("%d%d", &n, &m);
     build(, n, );
     for(int i = ; i < m; i++){
         scanf("%s", &op);
         if(op[] == 'Q'){
             scanf("%d%d", &a, &b);
             printf("%lld\n", Query(a, b, , n, ));
         }
         else{
             scanf("%d%d%lld", &a, &b, &c);
             Update(a, b, c, , n, );
         }
     }
     return ;
 }