UVA 12086

题目：http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=3238

简单树状数组。。

#include <cmath>
#include <ctime>
#include <iostream>
#include <string>
#include <vector>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <queue>
#include <map>
#include <set>
#include <algorithm>
#include <cctype>
#include <stack>
#include <deque>
using namespace std;
typedef long long LL;
#define EPS 10e-9
#define INF 0x3f3f3f3f
#define REP(i,n) for(int i=0; i<(n); i++)
const int maxn = 200000+100;
int n;
int c[maxn],d[maxn];
int lowbit(int x){
     return x&-x;
}
void add(int x,int d){
    while(x<=n){
      c[x]+=d;  x+=lowbit(x);
    }
}
int sum(int x){
    int ret=0;
    while(x>0){
       ret+=c[x];  x-=lowbit(x);
    }
    return ret;
}
int main(){
    char str[1000];  int x,y,ca=1; bool f=true;
    while(scanf("%d",&n)!=EOF){
        if(n==0) break;
         memset(c,0,sizeof(c));
         for(int i=1;i<=n;i++){
             scanf("%d",&d[i]);
             add(i,d[i]);
         }
         if( !f ) printf("\n");
         f = false;
         printf("Case %d:\n",ca++);
         while(1){
            scanf("%s",str);
            if(strcmp(str,"END")==0) break;
            scanf("%d%d",&x,&y);
            if(str[0]=='S'){
                int t=d[x];  d[x]=y;
                add(x,-t);  add(x,y);
            }
            else{
                printf("%d\n",sum(y)-sum(x-1));
            }
         }

    }
   return 0;
}