11723번: 집합

#include<cstdio>

#include<cstring>

bool s[21];

int main()

{

int m, x;

char com[7];

for (scanf("%d", &m); m--;)

{

scanf("%s", &com);

if (!strcmp("all", com))

for (int i = 1; i < 21; ++i)

s[i] = 1;

else if (!strcmp("empty", com))

for (int i = 1; i < 21; ++i)

s[i] = 0;

else

{

scanf("%d", &x);

if (!strcmp("add", com))

s[x] = 1;

else if (!strcmp("remove", com))

s[x] = 0;

else if (!strcmp("check", com))

printf("%d\n", s[x]);

else

s[x] = (s[x] == 1) ? 0 : 1;

}

}

}