C语言必会100题(19)。时间函数举例1/时间函数举例2/时间函数举例3/时间函数举例4/家庭财务管理小程序

特此鸣谢：鱼C_小甲鱼（B站up主）不二如是（鱼C论坛大佬）
题目来源：https://fishc.com.cn
注：这些题在网上都可以搜到，题下面的代码大多是流传下来的答案（我重新排了一下版，增加了可读性），部分是本人经过深思熟虑后编写的。

91，时间函数举例1

• 题目：无
• 程序源代码：

  #include <stdio.h>
  #include <time.h>
  
  int main()
  {
      // time_t就是long int型
      time_t lt;
      // 获取系统当前时间
      lt=time(NULL);
  
      // ctime函数，将日期和时间转换为字符串
      printf(ctime(&lt)); 
      
      // localtime是 把从1970-1-1零点零分到当前时间系统所偏移的秒数时间转换为本地时间，返回指针
      // asctime函数把储存的时间转换为字符串
      printf(asctime(localtime(&lt)));
      // gmtime函数转换后的时间没有经过时区变换，是UTC时间 
      printf(asctime(gmtime(&lt))); 
      
      return 0;
  }

92，时间函数举例2

• 题目：无
• 程序源代码：

  #include <stdio.h>
  #include <time.h>
  
  int main()
  {
      time_t start, end;
      int i;
  
      start = time(NULL);
      for(i = 0; i < 3000; i++) {
  
          printf("\1\1\1\1\1\1\1\1\1\1\n");
      }
      end = time(NULL);
  
      // 返回 time1 和 time2 之间相差的秒数 (time1 - time2)
      printf("The different is %6.3f\n", difftime(end, start));
  
      return 0;
  }

93，时间函数举例3

• 题目：无
• 程序源代码：

  #include <stdio.h>
  #include <time.h>
  
  int main()
  {
      clock_t start, end;
  
      // 该程序从启动到函数调用占用CPU的时间
      start = clock();
      for(i = 0; i < 10000; i++) {
          printf("\1\1\1\1\1\1\1\1\1\1\n");
      }
      end = clock();
      printf(": The different is %6.3f\n", (double)(end-start));
  
      return 0;
  }

94，时间函数举例4

• 题目：用之前的时间函数做一个猜数游戏，判断一个人反应快慢，要求评价用户的速度。
• 程序源代码：

  #include <time.h>
  #include <stdlib.h>
  #include <stdio.h>
  
  int main()
  {
      char c;
      clock_t start, end;
      time_t a, b;
      double var;
      int i, guess;
  
      // 随机生成一个种子数字，之前的C语言程序用过
      // 生成种子数字后，rand函数使用。
      srand(time(NULL));
      printf("do you want to play it(是否想要玩这个游戏?).('y' or 'n') \n");
  
      loop:
          while((c = getchar()) == 'y') {
  
              // 将获取到的数字取100余数，确保数字在1到100；
              i = rand() % 100;
              printf("\nplease input number you guess(输入你猜的数字):\n");
  
              // 该程序从启动到函数调用占用CPU的时间
              start = clock();
              // 获取系统当前时间
              a = time(NULL);
              scanf("%d", &guess);
  
              while(guess != i) {
  
                  if(guess > i) {
                      printf("please input a little smaller(请输入一个较小的数字).\n");
                      scanf("%d", &guess);
                  } else {
                      printf("please input a little bigger(请输入一个较大的数字).\n");
                      scanf("%d", &guess);
                  }
              }
  
              end = clock();
              b = time(NULL);
  
              printf(": It took you %6.3f seconds\n", var = (double)(end - start) / 18.2);
              printf(": it took you %6.3f seconds\n\n", difftime(b, a));
  
              if (var < 15) {
  
                  printf("You are very clever!\n\n");
              } else if (var<25) {
  
                  printf("you are normal!\n\n");
              } else {
  
                  printf("you are stupid!\n\n");
              }
              printf("Congradulations\n\n");
              printf("The number you guess is %d", i);
  
          }
  
          printf("\ndo you want to try it again?(\"yy\".or.\"n\")\n");
  
          // 这里用户必须输入两个y,因为输入两个y的时候程序才知道你输入了1个y;可以看一下putchar(c);
          if((c = getchar()) == 'y') {
  
              putchar(c);
              goto loop;
  
          }
  
          return 0;
  }

95，家庭财务管理小程序

• 题目：创建一个家庭财务管理小程序
• 程序源代码：

  /*money management system*/
  #include "stdio.h"
  #include "dos.h"
  main() {
  FILE *fp;
  struct date d;
  float sum,chm=0.0;
  int len,i,j=0;
  int c;
  char ch[4]="",ch1[16]="",chtime[12]="",chshop[16],chmoney[8];
  pp:
  clrscr();
  sum=0.0;
  gotoxy(1,1);
  printf("|---------------------------------------------------------------------------|");
  gotoxy(1,2);
  printf("| money management system(C1.0) 2000.03 |");
  gotoxy(1,3);
  printf("|---------------------------------------------------------------------------|");
  gotoxy(1,4);
  printf("| -- money records -- | -- today cost list -- |");
  gotoxy(1,5);
  printf("| ------------------------ |-------------------------------------|");
  gotoxy(1,6);
  printf("| date: -------------- | |");
  gotoxy(1,7);
  printf("| | | | |");
  gotoxy(1,8);
  printf("| -------------- | |");
  gotoxy(1,9);
  printf("| thgs: ------------------ | |");
  gotoxy(1,10);
  printf("| | | | |");
  gotoxy(1,11);
  printf("| ------------------ | |");
  gotoxy(1,12);
  printf("| cost: ---------- | |");
  gotoxy(1,13);
  printf("| | | | |");
  gotoxy(1,14);
  printf("| ---------- | |");
  gotoxy(1,15);
  printf("| | |");
  gotoxy(1,16);
  printf("| | |");
  gotoxy(1,17);
  printf("| | |");
  gotoxy(1,18);
  printf("| | |");
  gotoxy(1,19);
  printf("| | |");
  gotoxy(1,20);
  printf("| | |");
  gotoxy(1,21);
  printf("| | |");
  gotoxy(1,22);
  printf("| | |");
  gotoxy(1,23);
  printf("|---------------------------------------------------------------------------|");
  i=0;
  getdate(&d);
  sprintf(chtime,"%4d.%02d.%02d",d.da_year,d.da_mon,d.da_day);
  52
  for(;;) {
  gotoxy(3,24);
  printf(" Tab __browse cost list Esc __quit");
  gotoxy(13,10);
  printf(" ");
  gotoxy(13,13);
  printf(" ");
  gotoxy(13,7);
  printf("%s",chtime);
  j=18;
  ch[0]=getch();
  if(ch[0]==27)
  break;
  strcpy(chshop,"");
  strcpy(chmoney,"");
  if(ch[0]==9) {
  mm:
  i=0;
  fp=fopen("home.dat","r+");
  gotoxy(3,24);
  printf(" ");
  gotoxy(6,4);
  printf(" list records ");
  gotoxy(1,5);
  printf("|-------------------------------------|");
  gotoxy(41,4);
  printf(" ");
  gotoxy(41,5);
  printf(" |");
  while(fscanf(fp,"%10s%14s%f\n",chtime,chshop,&chm)!=EOF) {
  if(i==36) {
  getch();
  i=0;
  }
  if ((i%36)<17) {
  gotoxy(4,6+i);
  printf(" ");
  gotoxy(4,6+i);
  } else if((i%36)>16) {
  gotoxy(41,4+i-17);
  printf(" ");
  gotoxy(42,4+i-17);
  }
  i++;
  sum=sum+chm;
  printf("%10s %-14s %6.1f\n",chtime,chshop,chm);
  }
  gotoxy(1,23);
  printf("|---------------------------------------------------------------------------|");
  gotoxy(1,24);
  printf("| |");
  gotoxy(1,25);
  printf("|---------------------------------------------------------------------------|");
  gotoxy(10,24);
  printf("total is %8.1f$",sum);
  fclose(fp);
  gotoxy(49,24);
  printf("press any key to.....");
  getch();
  goto pp;
  } else {
  53
  while(ch[0]!='\r') {
  if(j<10) {
  strncat(chtime,ch,1);
  j++;
  }
  if(ch[0]==8) {
  len=strlen(chtime)-1;
  if(j>15) {
  len=len+1;
  j=11;
  }
  strcpy(ch1,"");
  j=j-2;
  strncat(ch1,chtime,len);
  strcpy(chtime,"");
  strncat(chtime,ch1,len-1);
  gotoxy(13,7);
  printf(" ");
  }
  gotoxy(13,7);
  printf("%s",chtime);
  ch[0]=getch();
  if(ch[0]==9)
  goto mm;
  if(ch[0]==27)
  exit(1);
  }
  gotoxy(3,24);
  printf(" ");
  gotoxy(13,10);
  j=0;
  ch[0]=getch();
  while(ch[0]!='\r') {
  if (j<14) {
  strncat(chshop,ch,1);
  j++;
  }
  if(ch[0]==8) {
  len=strlen(chshop)-1;
  strcpy(ch1,"");
  j=j-2;
  strncat(ch1,chshop,len);
  strcpy(chshop,"");
  strncat(chshop,ch1,len-1);
  gotoxy(13,10);
  printf(" ");
  }
  gotoxy(13,10);
  printf("%s",chshop);
  ch[0]=getch();
  }
  gotoxy(13,13);
  j=0;
  ch[0]=getch();
  while(ch[0]!='\r') {
  if (j<6) {
  strncat(chmoney,ch,1);
  j++;
  }
  if(ch[0]==8) 54 {
  len=strlen(chmoney)-1;
  strcpy(ch1,"");
  j=j-2;
  strncat(ch1,chmoney,len);
  strcpy(chmoney,"");
  strncat(chmoney,ch1,len-1);
  gotoxy(13,13);
  printf(" ");
  }
  gotoxy(13,13);
  printf("%s",chmoney);
  ch[0]=getch();
  }
  if((strlen(chshop)==0)||(strlen(chmoney)==0))
  continue;
  if((fp=fopen("home.dat","a+"))!=NULL);
  fprintf(fp,"%10s%14s%6s",chtime,chshop,chmoney);
  fputc('\n',fp);
  fclose(fp);
  i++;
  gotoxy(41,5+i);
  printf("%10s %-14s %-6s",chtime,chshop,chmoney);
  }
  }
  }