1004

题目大意:

有几个数，他们是2,3,5,7的倍数，把这些数排列出来，顺序输出规定的第几个数

解题思路:

先计算出最前的数，乘2，乘3，乘5，乘7，求出来这里面最小的，把最小的写入数组

代码:

#include <iostream>  
#include <cstdio>  
using namespace std;  
long long dp[5843];  
long long min(long long a, long long b, long long c, long long d)  
{  
    long long temp1 = a < b ? a : b;  
    temp1 = temp1 < c ? temp1 : c;  
    temp1 = temp1 < d ? temp1 : d;  
    return temp1;  
}  
int main()  
{  
      
    dp[1] = 1;  
    int a = 1, b = 1, c = 1, d = 1;  
    for (int i = 2; i <= 5842; ++i)  
    {  
        dp[i] = min(dp[a] * 2, dp[b] * 3, dp[c] * 5, dp[d] * 7);  
        if (dp[i] == dp[a] * 2) a++;  
        if (dp[i] == dp[b] * 3) b++;  
        if (dp[i] == dp[c] * 5) c++;  
        if (dp[i] == dp[d] * 7) d++;  
    }  
    int n;  
    while (cin>>n&&n)  
    {  
        if (n % 100 != 11 && n % 10 == 1)printf("The %dst humble number is %lld.
", n, dp[n]);  
        else  
            if (n % 100 != 12 && n % 10 == 2)printf("The %dnd humble number is %lld.
", n, dp[n]);  
            else  
                if (n % 100 != 13 && n % 10 == 3)printf("The %drd humble number is %lld.
", n, dp[n]);  
                else  
                    printf("The %dth humble number is %lld.
", n, dp[n]);  
    }  
    return 0;  
}