1027.c

平时acm训练时ac的源代码

#include <stdio.h>

int bracket;
int note;
char ch, ch1, ch2;

int main()
{
	bracket = 0 ;
	note = 0 ;
	while (1) {
		if ((ch = getchar()) == EOF) {
			if (note != 0 || bracket != 0) {
				printf("NO\n");
				return 0;
			}
			break;
		}
		if (ch == '(' && note == 0) {
			bracket++;
		}
		if (ch == '*') {
			if (ch1 == '(') {
				if (note == 0) bracket--;
				if (note == 0) note++;
			}
		}
		if (ch == ')') {
			if (ch1 == '*' && note != 0 && ch2 != '(') {
				note--;
				if (note < 0) { printf("NO\n"); 
return 0; }
			}
			else {
				if (note == 0) {
					bracket--;
					if (bracket < 0) { 
printf("NO\n"); return 0; }
				}
			}
		}
		if (ch == ' ' && bracket > 0 && note == 0) { 
			printf("NO\n"); return 0; }
		if (bracket > 0 && note == 0) {
			if (ch != '0' && ch != '1' && ch != '2' && ch != '3' && ch != '4' && ch != '5' && ch != '6' && ch != '7' && ch != '8' && ch != '9' && ch != '+' && ch != '-' && ch != '*' && ch != '/' && ch != '(' && ch != ')' && ch != '=' && ch != '\n' && ch != '\r' )
			{ printf("NO\n"); return 0; }
		}
		
		ch2 = ch1;
		ch1 = ch;
	}
	printf("YES\n");
	return 0;
}