这是一道树状数组题
#include<iostream>
using namespace std; const int maxn = 1e5 + ;
int tree[maxn], n, m;
char h;
int x, y;
void add(int k, int num){
while (k <= n){ tree[k] += num; k += k&-k; }
}
int sum(int k){
int sum = ;
while (k){
sum += tree[k];
k -= k&-k;
}
return sum;
} int main(){
cin >> n >> m;
while (m--){
cin >> h >> x >> y;
if (h == 'x')add(x, y);
else cout << sum(y) - sum(x - ) << endl;
}
}