1107.cpp

这是哈尔滨工业大学acmOJ的源代码

/*  This Code is Submitted by wywcgs for Problem 1107 on 2005-09-16 at 19:59:18 */ 
#include <stdio.h>

int main()
{
    int i, j, n, m, p;
    int pr[1001] = {1}, prime[180], prNum[1001];
    
    for(i = 2; i < 32; i++) {
        if(pr[i] == 0) {
            n = 1000 / i + 1;
            for(j = 2; j < n; j++) {
                m = j * i;
                if(m <= 1000) {
                    pr[m] = 1;
                }    
            }
        }
    }
    j = 0;
    for(i = 0; i < 1001; i++) {
        if(pr[i] == 0) {
            prime[j++] = i;
        }
        prNum[i] = j;
    }
    while(scanf("%d %d", &n, &m) == 2) {
        printf("%d %d:", n, m);
        if(prNum[n] % 2 == 0) {
            if(m * 2 > prNum[n]) {
                m = prNum[n] / 2;
            }
            p = prNum[n] / 2 + m;
            for(i = prNum[n]/2-m; i < p; i++) {
                printf(" %d", prime[i]);
            }
        } else {
            if(m * 2 - 1 > prNum[n]) {
                m = (prNum[n] + 1) / 2;
            }
            p = (prNum[n] + 1) / 2 + m - 1;
            for(i = (prNum[n]+1)/2-m; i < p; i++) {
                printf(" %d", prime[i]);
            }    
        }
        printf("\n\n");
    }    
    
    return 0;
}