//Declaration: char *strncat(char *str1, const char *str2, size_t count); //Return: returns *str1. #include <stdio.h> #include <string.h> int main(void) { char s1[80], s2[80]; unsigned int len; gets(s1); gets(s2); len = 79-strlen(s2); strncat(s2, s1, len); printf(s2); return 0; } /* 2 1 12*/