题解 | #公共子串计算#

//字符串匹配：
//asdfas
#define MAXROOM 1000
void getCommon(const char *str1, const char *str2, char* str3);
int stringLength(char * str);

int stringLength(char * str){
    int len = 0;
    while(*str != '\0'){
        len++;
        str++;
    }
    return len;
}
void getCommon(const char *str1, const char *str2, char* str3) {
	int len1, len2;
	int i, j, k;
	int max = 0;
	int start = -1;

	len1 = stringLength(str1);
	len2 = stringLength(str2);
    
	for (i = 0; i < len1; i++) {
		for (j = 0; j < len2; j++) {
			if (str1[i] == str2[j]) {
				for (k = 0; (str1[i + k] == str2[j + k] && str1[i + k] != '\0'); k++);
				if (max < k) {
					max = k;
					start = i;
				}
			}
		}
	}

	if (start == -1) {
		str3[0] = 0;
	}
	else {
		memcpy(str3, &str1[start], max);
		str3[max] = 0;
	}
}

int main() {
	char str1[MAXROOM]="";
	char str2[MAXROOM]="";
	char str3[MAXROOM] = "";
	gets(str1);
    gets(str2);

	getCommon(str1, str2, str3);
	printf("%d\n", strlen(str3));
    return 0;
}