一则可以随机产生四则运算的c程序！

#include"stdio.h" #include"time.h" /* 定义随机数发生器头文件 */ #include"conio.h" /* 定义清屏函数 */ #include "stdlib.h" /* 定义随机数函数 */ void account(); /* 声明cccount函数 */ void mize(); /* 声明随机数函数 */ int a,b,c,d,e,k,g,h,j=0; void mize() { randomize( ); /* 初始化随机数发生器 */ a=rand()/1000; /* 除1000使随机数变小 */ b=rand()/1000; c=rand()/1000; d=rand()/1000; } unsigned char t; main() { int n; while(1) { clrscr( ); printf(" ***************************************************\n"); printf(" Arithmetic Exercise System of Pupil\n"); printf(" ***************************************************\n"); printf(" 1.Addition Exercise\n"); printf(" 2.Subtract Exercise\n"); printf(" 3.Multiplication Exercise\n"); printf(" 4.Division Exercise\n"); printf(" 0.Quit\n"); printf("Choice(0--4):"); while(scanf("%d",&n)!=1) /* 判断输入是否为真0-4 */ { while(getchar()!='\n'); /* 空格进行清屏 */ clrscr( ); printf("you input is wrong!\n"); /* 提示输入有误 */ puts("please input a right number:\n"); } if(n>=0&&n<=4) { clrscr( ); switch(n) /* 如果匹配0-4则进行运行 */ { case 0: return 0; z: case 1: account(); printf("\n"); f1: printf("\nContinue(Y/N)?"); /* 定义显示Continue (Y/N)? */ t=getch(); printf("you input is %c\n",t); if(!((t=='N'||t=='n')||(t=='Y'||t=='y'))) goto f1; /* 循环f1,以确定每次计数结束后还回Continue (Y/N)? */ if(t=='Y'||t=='y') {clrscr( ); goto z;} else j=0;break; p: case 2: account(); printf("\n"); f3: printf("\nContinue(Y/N)?"); t=getch(); printf("you input is %c\n",t); if(!((t=='N'||t=='n')||(t=='Y'||t=='y'))) goto f3; if(t=='Y'||t=='y') {clrscr( ); goto p;} else j=0; break; x: case 3: account(); printf("\n"); f2: printf("\nContinue(Y/N)?"); t=getch(); printf("you input is %c\n",t); if(!((t=='N'||t=='n')||(t=='Y'||t=='y'))) goto f2; if(t=='Y'||t=='y') {clrscr( ); goto x;} else close(); u: case 4: account(); printf("\n"); /* 调用account()函数 */ f: printf("\nContinue(Y/N)?"); t=getch(); printf("you input is %c\n",t); if(!((t=='N'||t=='n')||(t=='Y'||t=='y'))) goto f; if(t=='Y'||t=='y') {clrscr( ); goto u;} else j=0; break; } } } getch(); } int add,sub,Mul,Div,t1,s,i=0; void account(int n) /* 定义account 函数 */ { mize(); while(1) { switch(n) { case 1: printf("%d+%d=",a,b);scanf("%d",&e); add=a+b; /* 定义加法运算 */ t1=e; /* 将答案赋给t1，以判断输入答案是否正确 */ s=a+b; /* 以确定运行3次后能给出题目答案 */ break; case 2: if(a>b) /* 确保不会出现负数 */ printf("%d-%d=",a,b);scanf("%d",&k); sub=a-b; t1=k; s=a-b;break; case 3: printf("%d*%d=",c,d);scanf("%d",&g); Mul=c*d; t1=g;s=Mul;break; case 4: if(a/b!=0) printf("%d/%d=",a,b);scanf("%d",&h); Div=b/a; t1=h; s=b/a;break; } if(i<4) { if(t1==s&&i==1) { printf("OK !Very Good!\n"); break; } else if(t1==s&&i==2) { printf("OK! Good!\n"); break; } else if(t1==s&&i==3) { printf("OK!"); break; } else { clrscr( ); printf("Wrong! Do it again\n"); if(i==2) { clrscr( ); printf("Wrong! The right answer is: %d\n",s); break; } i++; /* 每次运算完自动加1，以确定是否运行够3次 */ } } } }