2398560_wa.cc

北大大牛代码 1240道题的原代码 超级权威

#include <stdio.h>
#include <string.h>
#include <math.h>
char Exp[300];
bool var[6];

bool cal(char str[])
{
	int i, n1, n2;
	char t1[300], t2[300];

	if(strlen(str)==1)
		return var[str[0]-'p'];
	if(str[0]=='N')
		return !cal(&str[1]);
	n1 = 0;n2 = 0;
	for(i = 1; str[i]!='\0'; i++)
	{
		if(str[i]<='Z'&&str[i]!='N')
			n1++;
		else
			n2++;
		if(n1+1==n2)
			break;
	}
	strcpy(t2,&str[i+1]);
	str[i+1] = '\0';
	strcpy(t1,&str[1]);
	if(str[0]=='K')
		return cal(t1)&&cal(t2);
	if(str[0]=='A')
		return cal(t1)||cal(t2);
	if(str[0]=='E')
		return cal(t1)==cal(t2);
	return (cal(t1)==0)||cal(t2);
}

void solve()
{
	int i, j;
	char Tmp[300];

	
	for(i = 0; i < 32; i++)
	{
		for(j = 0; j < 5; j++)
			var[j] = (i&(int)pow(2,j))!=0;
		strcpy(Tmp,Exp);
		if(!cal(Tmp))
		{
			printf("not\n");
			return ;
		}
	}
	printf("tautology\n");
}

int main()
{
	while(scanf("%s",Exp)==1&&Exp[0]!='0')
		solve();
	return 1;
}