C语言学习 - 0002 优秀代码学习

#include<stdio.h>
#include<stdlib.h>
 
#define INI_LEN 20
#define INC 10
char* get_input();
void output(char* array);
int main(){
    printf("请输入字符串，双回车结束：\n");
    char *string = get_input();
     
    output(string);
    getchar();
    return 0;
}
//输入函数
char* get_input(){
    char* string = (char*)malloc(INI_LEN*sizeof(char));
    int len = INI_LEN;
    int i = 0,cnt = 0;
    while (cnt != 2){
        if (i + 1 == len){
            len += INC;
            char* tmp = string;
            string = (char*)malloc(len*sizeof(char));
            for (int k = 0; k <= i; ++k)
                string[k] = tmp[k];
            free(tmp);
        }
        string[i] = getchar();
        if (string[i] == '\n')
            cnt++;
        else
            cnt = 0;
        i++;
    }
    string[i-1] = '\0';
    return string;
 
}
//输出函数
void output(char* array){
    int tag = 1,cnt = 1;
    for (int i = 0; array[i]!='\0'; ++i){
        if (tag == 1){
            tag = 0;
            if (array[i] != '\n'&&array[i] != '\0')
                printf("%d.  ", cnt);
        }
        if (array[i] == '\n'){
            if (array[i+1] != '\n'&&array[i+1] != '\0'){
                tag = 1;
                cnt++;
            }
        }
        printf("%c", array[i]);
    }
}