将一个字符串翻转

#include <stdio.h>#include <string.h>int len;char *reverse(char *str,int len){char temp;if(len > 1){temp = str[len-1];str[len-1] = str[0];str[0] = temp;len = len -2;reverse(++str,len);}return(str-1);}int main(void){char s[10] = "abcdefghij";int len = strlen(s);printf("%s\n",reverse(s,len));return 0;}