UVA 12086 Potentiometers 树状数组

//#pragma comment(linker, "/STACK:1024000000,1024000000")
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<algorithm>
#include<iostream>
#include<sstream>
#include<cmath>
#include<climits>
#include<string>
#include<map>
#include<queue>
#include<vector>
#include<stack>
#include<set>
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
#define pb(a) push_back(a)
#define INF 0x1f1f1f1f
#define lson idx<<1,l,mid
#define rson idx<<1|1,mid+1,r
#define PI  3.1415926535898
template<class T> T min(const T& a,const T& b,const T& c) {
    return min(min(a,b),min(a,c));
}
template<class T> T max(const T& a,const T& b,const T& c) {
    return max(max(a,b),max(a,c));
}
void debug() {
#ifdef ONLINE_JUDGE
#else

    freopen("d:\\in.txt","r",stdin);
    freopen("d:\\out1.txt","w",stdout);
#endif
}
int getch() {
    int ch;
    while((ch=getchar())!=EOF) {
        if(ch!=' '&&ch!='\n')return ch;
    }
    return EOF;
}

int da[200200];
int c[200200];
int n;

int add(int x,int v)
{
    while(x<=n)
    {
        c[x]+=v;
        x=x+(x&-x);
    }
    return 0;
}
int sum(int x)
{
    int a=0;
    while(x>0)
    {
        a+=c[x];
        x=x-(x&-x);
    }
    return a;
}
int main()
{
    int ca=0;
    while(scanf("%d",&n)!=EOF&&n)
    {
        if(ca!=0)
            printf("\n");
        printf("Case %d:\n",++ca);
        memset(c,0,sizeof(c));
        for(int i=1;i<=n;i++)
        {
            scanf("%d",&da[i]);
            add(i,da[i]);
        }
        char op[100];
        while(scanf("%s",op)!=EOF&&op[0]!='E')
        {
            int a,b;
            scanf("%d%d",&a,&b);
            if(op[0]=='S')
            {
                add(a,b-da[a]);
                da[a]=b;
            }else
            printf("%d\n",sum(b)-sum(a-1));
        }
    }
    return 0;
}