poj 1595

比较水的一道题。

//============================================================================
// Name        : 1595.cpp
// Author      : 
// Version     :
// Copyright   : Your copyright notice
// Description : Hello World in C++, Ansi-style
//============================================================================

#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;

bool flag[1010];
int num[1010];
int N, C, k;


int main() {
	freopen("a.txt", "r", stdin);
	for(int i = 2;i <= 1010/2;i++){
		if(flag[i] == false){
			for(int j = i*2;j <= 1010;j+=i){
				flag[j] = true;
			}
		}
	}
	while(scanf("%d%d", &N, &C)!=EOF){
		printf("%d %d:", N, C);
		k = 0;
		for(int i = 1;i <= N;i++){
			if(flag[i] == false){
				num[++k] = i;
			}
		}
		if(k%2 == 0){
			if(C*2 <= k){
				for(int i = (k-(C*2))/2+1, t = 1;t <= C*2;t++, i++){
					printf(" %d", num[i]);
				}
				printf("\n");
			}
			else{
				for(int i = 1;i <= k;i++){
					printf(" %d", num[i]);
				}
				printf("\n");
			}
		}
		else{
			if(C*2-1 <= k){
				for(int i = (k-(C*2-1))/2+1, t = 1;t <= C*2-1;t++, i++){
					printf(" %d", num[i]);
				}
				printf("\n");
			}
			else{
				for(int i = 1;i <= k;i++){
					printf(" %d", num[i]);
				}
				printf("\n");
			}
		}
		printf("\n");
	}
	return 0;
}