#include <stdio.h>

int strlen_1st(char c[]) {
	int result = 0;
	do { result += 1; } while (c[result] != '\0');
	return result;
}

int strlen_2nd(char c[]) {
	char* p = c;
	while (*p++); return p - c - 1;
}

int strcmp_1st(char s1[], char s2[]) {
	int len1 = 0, len2 = 0, i = 0;
	while (len1 == 0 || len2 == 0) {
		if (len1 == 0 && s1[i] == '\0') { len1 = i; }
		else if (len2 == 0 && s2[i] == '\0') { len2 = i; }
		i++; 
	}
	return len1 - len2;
}

void strcpy(char s1[], char d1[]) {
	for (int i = 0; i < 9999; i++) {
		if (s1[i] != '\0') {
			d1[i] = s1[i];
		}
		else {
			break;
		}
	}
}

void strcat_1st(char* s1, char* s2) {
	while (*s2) s2++;
	while (*s2++ == *s1++);
}

int strchr(char s1[], char sym) {
	int i = 0;
	while (s1[i] != sym) {
		i++;
		if (i >= strlen_1st(s1)) { printf("there's is such symbol"); break; }
	}
	return i;
}

void main() {
	char str[11] = "string";
	char str2[12] = "string2";
	char str3[13] = "stringthree";
	char strx[11] = "string4";
	char etp[14] = "";
	char* Word; 
	printf("%d\n", strlen_1st(str));
	printf("%d\n", strlen_2nd(str2));
	printf("%d %d\n", strcmp_1st(str, str2), strcmp_1st(str, str3));
	strcpy(str, etp); printf("%s\n", etp);
	strcat(str3, etp); printf("%s\n", str3);
	printf("n at index %d - in %s\nf", strchr(strx, 'n'), strx);
}