poj 2886 Who Gets the Most Candies?

Problem: 2886		User: shu_dayang
Memory: 11104K		Time: 1125MS
Language: C++		Result: Accepted


#include<iostream>
#include<cstdio>
#include<cstring>
#define MID(a,b)  ((a + b) >> 1)
using namespace std;

const int MAXN = 500005;
int sum[MAXN << 2];
char name[MAXN][10];
int val[MAXN];

int RPrime[]={//反素数
    1,2,4,6,12,24,36,48,60,120,180,240,360,720,840,1260,1680,2520,5040,7560,10080,15120,
    20160,25200,27720,45360,50400,55440,83160,110880,166320,221760,277200,332640,498960,
    554400
};

int fact[]={//反素数约数个数
    1,2,3,4,6,8,9,10,12,16,18,20,24,30,32,36,40,48,60,64,72,80,84,90,96,100,108,120,128,
    144,160,168,180,192,200,216
};

void PushUp(int rt)
{
    sum[rt] = sum[rt << 1] + sum[(rt << 1) + 1];
}

void build(int l, int r, int rt)
{
    if(l == r)
    {
        sum[rt] = 1;
        return;
    }
    int mid = MID(l, r);
    build(l, mid, rt << 1);
    build(mid +1, r, (rt << 1) + 1);
    PushUp(rt);
}

int update(int p, int l, int r, int rt)
{
    int res;
    if(l == r)
    {
        sum[rt] --;
        return l;
    }
    int mid = MID(l, r);
    if(p <= sum[rt << 1])
        res = update(p, l, mid, rt << 1);
    else
        res = update(p - sum[rt << 1], mid + 1, r, rt << 1 | 1);
    PushUp(rt);
    return res;
}

int main()
{
    int N,K,&mod = sum[1];
    while(~scanf("%d%d",&N,&K))
    {
        int luck;
        for(int i = 0; i < N; i++)
            if(N < RPrime[i])
            {
                luck = i - 1;
                break;
            }
        build(1,N,1);
        int count = 0;

        for(int i = 1; i <= N; i++)
        {
            scanf("%s%d",name[i],&val[i]);
        }
        int k = K;
        int pos = 0;
        for(int i=0;i<RPrime[luck];i++)
        {
            if(val[pos]>0)
                k=((k+val[pos]-2)%mod+mod)%mod+1;
            else
                k=((k+val[pos]-1)%mod+mod)%mod+1;
            pos=update(k,1,N,1);
        }
        printf("%s %d\n",name[pos],fact[luck]);
    }
}