NYOJ663 弟弟的作业

原题链接

#include <stdio.h>
//#include <stdlib.h>

int main(){
	int a, b, c, count = 0;
	char ch, sign, s[5];
	while(scanf("%d%c%d=%s", &a, &sign, &b, s) != EOF){
		if(s[0] == '?') continue;
		if(sign == '+') c = a + b;
		else c = a - b;
		a = ch = 0;
		for(b = 0; s[b] != '\0'; ++b){
			if(s[b] == '-'){
				ch = 1;
				continue;
			}
			a = a * 10 + s[b] - '0';
		}
		if(ch) a = -a;
		if(a == c) ++count;
	}
	printf("%d\n", count);
	//system("pause");
	return 0;
}

另一种思路：

#include <stdio.h>
//#include <stdlib.h>

int main(){
	int a, b, c, j, k, count = 0;
	char s[15];
	while(~scanf("%s", s)){
		j = sscanf(s, "%d+%d=%d", &a, &b, &c);
		k = sscanf(s, "%d-%d=%d", &a, &b, &c);
		if(j == 3 && a + b == c) ++count;
		else if(k == 3 && a - b == c) ++count;
	}
	printf("%d\n", count);
	//system("pause");
	return 0;
}