== 1 == {{{ //strcpy char* strcpy(char s1[], char s2[]) { int i = 0; while (*(s2 + i)) { s1[i] = s2[i]; i++; } s1[i] = s2[i]; return s1; } }}} == 2 == {{{ //strlen int strlen(char* p) { int length = 0, i = 0; while (*(p + i)) { length++; i++; } return length; } }}} == 3 == {{{ //strcat void strcat(char s1[], char s2[]) { for (int i = strlen(s1), j = 0; i <= strlen(s1) + strlen(s2); i++, j++) { s1[i] = s2[j]; } } }}} == 4 == {{{ //strcmp int strcmp(char s1[], char s2[]) { int i = 0; while (s1[i] != '\0' || s2[i] != '\0') { if (s1[i] > s2[i]) return 1; else if (s1[i] < s2[i]) return -1; i++; } return 0; } }}}