题目链接:
https://www.acwing.com/problem/content/description/1266/
题解:
模板题,记query()、add()、lowbit()函数即可
AC代码:
#include <iostream> #include <cstdio> #include <cstring> #include <algorithm> using namespace std; const int N = 1e5+5; int a[N]; int tr[N]; int n,m; int k,x,y; int lowbit(int x){ return x&-x; } int add(int x,int v){ for(int i = x;i<=n;i+=lowbit(i)) tr[i] += v; } int query(int x){ int sum = 0; for(int i=x;i>0;i-=lowbit(i)) sum+=tr[i]; return sum; } 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]); while(m--){ scanf("%d%d%d",&k,&x,&y); if(k == 1) add(x,y); else{ printf("%d\n",query(y) - query(x-1)); } } return 0; }