UVa 443 - Humble Numbers

题目：求由{2,3,5,7}组成那的数字集合的第n个数字。

分析：利用4根指针，对应每个数字当前对应的因子，每次取最小的数值，指针后移。注意相等的情况。

注意：输出的计数法。

[cpp]
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int d[ 5850 ];
int v[4] = {2,3,5,7};
int p[4] = {1,1,1,1};

int main()
{ www.zzzyk.com
    int count = 2; d[1] = 1;
    while ( count <= 5842 ) {
        int min = 2000000001;
        for ( int i = 0 ; i < 4 ; ++ i )
            if ( min > v[i]*d[p[i]] )
                min = v[i]*d[p[i]];
        for ( int i = 0 ; i < 4 ; ++ i )
            if ( min == v[i]*d[p[i]] )
                p[i] ++;
        d[count ++] = min;
    }
    int n;
    while ( scanf("%d",&n) && n ) {
        printf("The %d",n);
        if ( n%100 == 11 || n%100 == 12 || n%100 == 13 )
            printf("th");
        else if ( n%10 == 1 )
            printf("st");
        else if ( n%10 == 2 )
            printf("nd");
        else if ( n%10 == 3 )
            printf("rd");
        else printf("th");
        printf(" humble number is %d.\n",d[n]);
    }
    return 0;
}

补充：软件开发 , C++ ,