算法竞赛入门经典 例3-1开灯问题

#include <cstdio>
#include <cstring>
bool light[100];
int main(){
int n = 7;
int k = 3;
memset(light, false, sizeof(light));
for (int i = 1; i <= k; ++i){
for (int j = 1; j * i <= n; ++j){
light[j * i] = !light[j * i];
}
}
for (int i = 1; i <= n; ++i){
if (light[i])
printf("%d ", i);
}
}