树状数组单点修改区间查询

// by spli
#include<cstring>
#include<cstdio>
#include<algorithm>
#include<iostream>
using namespace std;

const int N=500010;
int n,m;
int a
,c
;

int lowbit(int x){return x&(-x);}

void add(int pos,int v){
for(int i=pos;i<=n;i+=lowbit(i))
c[i]+=v;
}

int query(int x){
int ret=0;
for(int i=x;i>=1;i-=lowbit(i))
ret+=c[i];
return ret;
}

int main(){
scanf("%d%d",&n,&m);
for(int i=1;i<=n;++i) scanf("%d",&a[i]);
for(int i=1;i<=n;++i) add(i,a[i]);
int op,x,y;
while(m--){
scanf("%d%d%d",&op,&x,&y);
if(op==1) add(x,y);
else printf("%d\n",query(y)-query(x-1));
}
return 0;
}