[Leetcode]-Longest Common Prefix

// 1、判断strs的长度，如果为0则返回空字符
// 2、找出strs中最短的字串
// 3、采用循环查询的方式依次匹配是否和最短字串相符
// 4、循环中实时更新查询的长度index

#include <stdlib.h>#include <stdio.h>#include <string.h>char* longestCommonPrefix(char** strs, int strsSize) {    if(strsSize < 1)        return "";    int index = strlen(strs[0]) ;    int i = 0, j =0, m=0;    for(i=0;i<strsSize-1;i++) //求取最短字串的长度    {        if(strlen(strs[i+1])<strlen(strs[i]))        {            index = strlen(strs[i+1]);            m = i+1;        }    }    printf("the most short size of string is :%d \n ",index);    char *r = (char*)malloc(sizeof(char) * index);    strcpy(r,strs[m]);    printf("r is :%s \n ",r);    int tem = 0;    for(i=0;i<strsSize;i++)    {        tem = 0;        for(j=0;j<index;j++)        {            if(r[j] == strs[i][j])            {                tem++;            }            else            {                r[j] = '\0';                break;            }           }        if(tem == 0)  return ("");        if(tem < index) index = tem;    }    return r;}int main(char argc,char** argv){    char a3[][30] = {{"xiabodan_firstpoint!"},{"xiabodan_second!"},{"xiabodan_thirdpoint!"}};    char *a0 = "xiabodan_first!";    char *a1 = "xiabodan_secondpoint!";    char *a2 = "xiabodan_thirdpoint!";    char *p3[3] ;    int i = 0;    for(i=0;i<3;i++)    {        p3[i] = a3[i];    }    //p3[0] = a0;    //p3[1] = a1;    //p3[2] = a2;    //printf("strlen  str is: %d \n",strlen(p3));     char* lpc = longestCommonPrefix(p3,3);    printf("longestCommonPrefix str is: %s \n",lpc);  //输出应该是xiabodan_才对}