/*实现两个字符串的连接。例如：输入dfdfqe和12345时，则输出dfdfqe12345*/#include <stdio.h>#include <string.h>void scat (char s1[], char s2[]);int main() {char s1[80], s2[80];gets(s1);gets(s2);scat(s1, s2);puts(s1

/*计算正整数num的各位上的数字之积。例如：输入252，则输出应该是20*/#include <stdio.h>long fun(long num){long k = 1;do{k *= num % 10;num /= 10;} while (num);return k;}int main(){long n;printf("\nPlease enter a number:.