例题：找出字符串中最长数字串

题目：输入一个字符串，找出字符串中最长数字

#include<stdio.h>char num_long(char *str); int main(void){char str[100];printf("Please input a string with numbers:\n");scanf("%[^\n]",str);    num_long(str);                 //调用查找最长数字串函数}char num_long(char *str){int loc = 0,max_loc = 0;int len = 0,max_len = 0;int flag = 0;int i = 0;while(str[i] != '\0')                   {if(str[i] >= '0' && str[i] <= '9'){if(flag == 0)         //标志是否是数字{flag = 1;loc = i;          //记录数字串首地址}len++;                 //记录字符串长度}else{if(flag == 1){flag = 0;if(max_len < len)        //比较出最长字符串{max_len = len;max_loc = loc;}len = 0;               //置0，以便记录下一个数字串长度}}i++;}for(i = max_loc; i < (max_loc + max_len); i++){printf("%c",str[i]);}}

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