简约树状数组模板

使用了c++11的语法糖Lambda表达式

#include<cstdio>
using namespace std;
int tree[510000],s,n,m,a1,a2,a3;
int main() {
    auto add=[](int x,int k){while (x<=n)tree[x]+=k,x+=x& -x;};
    auto sum=[](int x){int ans=0;while (x!=0)ans+=tree[x],x-=x & -x;return ans;};
	scanf("%d%d",&n,&m);
	for (int i=1; i<=n&&scanf("%d",&s); i++) add(i, s);
	while (m--&&scanf("%d%d%d",&a1,&a2,&a3))if(a1==1)add(a2,a3);else printf("%d\n",sum(a3)-sum(a2-1));
	return 0;
}

压行真是太开心了