树状数组

int lowbit(int x){    return x&(-x);  }//单点更新，区间查询int sum(int x){    int ret=0;    while(x){        ret+=ss[x];        x-=lowbit(x);       }    return ret; }void add(int x,int num){    while(x<=n){        ss[x]+=num;        x+=lowbit(x);       }   }

相关题目

1. hdu 5775