兩端輸出<字符從兩端移動，向中間匯聚>。模擬三次密碼輸入

編寫代碼，演示任意一個字符串從兩端移動，向中間匯聚，並以這樣的形式輸出。

#include<windows.h>

Sleep（n毫秒）

延遲n毫秒再輸出

分析：

代碼：

#include<stdio.h>

#include<stdlib.h>

#include<string.h>

#include<Windows.h>

int main()

{

                 int i = 0;

                printf( "輸入字符的個數n:_" );

                 int n= 0;

                scanf( "%d" ,&n);

                 char *p1 = (char *)malloc(n + 1);

                 char *p2 = (char *)malloc(n+ 1);

                 if (p1 == NULL || p2 == NULL)

                {

                                printf( "out of memory\n" );

                                exit(1);

                }

                scanf( "%s" , p1);

                 int len = strlen(p1);

                 for (i = 0; i < len; i++)

                {

                                p2[i] = '#' ;

                }

                p2[len] = '\0' ;

                 int left = 0;

                 int right =len-1;

                printf( "%s\n" ,p2);

                 while (left <= right)

                {

                                Sleep(1000);     //睡上一秒，再輸出

                                p2[left] = p1[left];

                                p2[right] = p1[right];

                                printf( "%s\n" ,p2);

                                left++;

                                right--;

                }

                free(p1);

                free(p2);

                system( "pause" );

                 return 0;

}

或者：

int main()

{

                 int i = 0;

                 char p1[100];

                 char p2[100];

                scanf( "%s" , p1);

                 int len = strlen(p1);

                 for (i = 0; i < len; i++)

                {

                                p2[i] = '#' ;

                }

                p2[len] = '\0' ;

                 int left = 0;

                 int right = len - 1;

                printf( "%s\n" , p2);

                 while (left <= right)

                {

                                Sleep(1000);

                                p2[left] = p1[left];

                                p2[right] = p1[right];

                                printf( "%s\n" , p2);

                                left++;

                                right--;

                }

                system( "pause" );

                 return 0;

}

試分析兩個代碼對內存的利用率。

模擬三次密碼登陸：初始密碼123456

#include<stdio.h>

#include<stdlib.h>

#include<string.h>

int main()

{

                 int i = 0;

                 char arr[10];

                 while (i < 3)

                {

                                gets(arr);

                                 if (strcmp(arr,"123456" )== 0)

                                {

                                                printf( "登陸成功\n" );

                                                system( "pause");

                                                 return 0;

                                }

                                i++;

                                printf( "登陸失敗\n" );

                }

                printf( "已經用完三次機會了\n" );

                system( "pause");

                 return 0;

}