1 #include <stdio.h> 2 #include <string.h> 3 #define N 5  4  5  6 char *mycpy(char *s1, char *s2) 7 { 8     //数组型 9 /*    int i;10     while(s2[i] != ‘\0‘) {11         s1[i] = s2[i];12         i++;13     } 14     s1[i] = ‘\0‘;15     return s1;    */16     //指针型17     char *p = s1;18     while(*s2 != ‘\0‘) {19         *s1 = *s2;20         s1++;21         s2++;22     } 23     *s1 = ‘\0‘;24     return p;25 }26 27 int main()28 {29     char s1[100];30     char s2[100];31 //    gets(s1);32 //    gets(s2);33     fgets(s1, N, stdin);34     if(s1[strlen(s1) - 1] == ‘\n‘) {      // 去掉换行符35         s1[strlen(s1) - 1] = ‘\0‘;   36     }37     fflush(stdin);                        //清空缓冲区（具体请看gets和fgets函数的区别）38     fgets(s2, N, stdin);39     if(s2[strlen(s2) - 1] == ‘\n‘) {      // 去掉换行符40         s2[strlen(s2) - 1] = ‘\0‘;   41     }42     printf("%s", mycpy(s1, s2));43     44     return 0;45 }