（HDU）1058 --Humble Numbers( 丑数）

题目链接：http://vjudge.net/problem/HDU-1058

这题有点难度，自己写了半天依旧TLE，参考了其他人的博客。

http://blog.csdn.net/pythonfx/article/details/7292835

http://blog.csdn.net/x_iya/article/details/8774087

第二个人的博客用的是DP，放在基础题里面不大合适。

#include <stdio.h>
int f[5843],n;
int i,j,k,l;

int min(int a,int b,int c,int d){
    int min=a;
    if(b<min) min=b;
    if(c<min) min=c;
    if(d<min) min=d;

    if(a==min) i++;
    if(b==min) j++;
    if(c==min) k++;
    if(d==min) l++;

    return min;
}

int main(){
    i=j=k=l=1;
    f[1]=1;
    for(int t=2;t<=5842;t++)
        f[t]=min(2*f[i],3*f[j],5*f[k],7*f[l]);

    while(scanf("%d",&n)&&n!=0){
        if(n%10==1&&n%100!=11)
            printf("The %dst humble number is %d.
",n,f[n]);
        else if(n%10==2&&n%100!=12)
            printf("The %dnd humble number is %d.
",n,f[n]);
        else if(n%10==3&&n%100!=13)
            printf("The %drd humble number is %d.
",n,f[n]);
        else
            printf("The %dth humble number is %d.
",n,f[n]);
    }
    return 0;
}

#include <iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
long long f[6000];
int main()
{
    int n;
    int prime[4]={2,3,5,7};
    f[1]=1;
    for(int i=2;i<=5842;i++)
    {
        f[i]=2000000001;
        for(int j=0;j<4;j++)
        {
            for(int k=i-1;k>0;k--)
            {
                if(f[k]*prime[j]<=f[i-1])
                    break;
                if(f[k]*prime[j]<f[i])//?????????
                    f[i]=f[k]*prime[j];
            }
        }
    }
    while(scanf("%d",&n),n)
    {
        if(n%10==1&&n%100!=11)
            printf("The %dst humble number is %lld.
",n,f[n]);
        else if(n%10==2&&n%100!=12)
            printf("The %dnd humble number is %lld.
",n,f[n]);
        else if(n%10==3&&n%100!=13)
            printf("The %drd humble number is %lld.
",n,f[n]);
        else
            printf("The %dth humble number is %lld.
",n,f[n]);
    }
    return 0;
}