POJ 3468 A Simple Problem with Integers 区间和更新，区间和查找

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#include<algorithm>
#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<queue>
#include<map>
#define LL long long
#define bug puts("***********");
#define lson L,mid,ind<<1
#define rson mid+1,R,ind<<1|1
#define lind ind<<1
#define rind ind<<1|1
using namespace std;
const int N=100010;
LL sum[N*4];
LL lazy[N*4];
int n,m;
void pushdown(int ind,int L,int R){
if(lazy[ind]!=0){ ///向下更新，孩子lazy需要更新,孩子的区间和也需要更新
lazy[rind]+=lazy[ind];
lazy[lind]+=lazy[ind];
sum[lind]+=lazy[ind]*((R+L)/2-L+1);
sum[rind]+=lazy[ind]*(R-(R+L)/2);
lazy[ind]=0;
}
}
void pushup(int ind){
sum[ind]=sum[lind]+sum[rind];
}
void build(int L,int R,int ind){
if(L==R){
scanf("%lld",&sum[ind]);
return ;
}
int mid=L+(R-L)/2;
build(lson);
build(rson);
pushup(ind);
}
void update(int sl,int sr,int val,int L,int R,int ind){
if(sl<=L&&sr>=R){
lazy[ind]+=val;
sum[ind]+=val*(R-L+1);
return ;
}
if(sl>R||sr<L) return ;
pushdown(ind,L,R);
int mid=L+(R-L)/2;
update(sl,sr,val,lson);
update(sl,sr,val,rson);
pushup(ind);
}
LL Query(int sl,int sr,int L,int R,int ind){
LL msum=0;
if(sl<=L&&sr>=R){
return sum[ind];
}
if(sl>R||sr<L) return 0;
pushdown(ind,L,R);
// pushup(ind);
int mid=L+(R-L)/2;
msum+=Query(sl,sr,lson);
msum+=Query(sl,sr,rson);
return msum;
}
int u,v,d;
int main(){
memset(sum,0,sizeof(sum));
memset(lazy,0,sizeof(lazy));
scanf("%d%d",&n,&m);
build(1,n,1);
char s[10];
while(m--){
scanf("%s",s);
if(s[0]=='Q'){
scanf("%d%d",&u,&v);
printf("%lld\n",Query(u,v,1,n,1));
}
else{
scanf("%d%d%d",&u,&v,&d);
update(u,v,d,1,n,1);
}
}
return 0;
}