HDOJ 1262 尋找素數對

~~~題目鏈接~~~

水過

#include <stdio.h>
#include <string.h>
int main()
{
    int i = 0, j = 0, sum = 0, p[10002] = {0};
    p[0] = p[1] = 0;
    for(i = 2; i<10002; i++)
        if(i%2) p[i] = 1;
        else p[i] = 0;
    p[2] = 1;
    for(i = 2; i*i<10002; i++)
    {
        if(p[i])
            for(j = i*i; j<10002; j += i)
                p[j] = 0;
    }
    while(scanf("%d", &sum) != EOF)
    {
        for(i = sum/2; i>1; i--)
        {
            if(p[i] && p[sum-i])
            {
                printf("%d %d\n", i, sum-i);
                break;
            }
        }
    }
    return 0;
}