#include <stdio.h>
#include <stdlib.h>
#include <time.h>

main()
{
for (;;){
  switch (menu()){
    case '1':test();break;
    case '2':practise();break;
    case '3':exit(0);
    }
  }
}

menu()
{
char c;
do{
  clrscr();
  printf("\n    1.测试\n");
  printf("    2.练习\n");
  printf("    3.退出\n");
  printf("\n请选择(1或2或3):");
  c=getche();
  }while(c<'1'||c>'3');
return c;
}

test()
{
int ts,i,m,n,s,r=0;
ts=numsoftest();
randomize();
for (i=1;i<=ts;i++){
  do {
    m=num();n=num();
    }while ((m+n)>9);
  printf("%d) %d+%d=",i,m,n);
  scanf("%d",&s);
  if (s==m+n) r++;
  }
printf("成绩:%d\n",100*r/ts);
printf("按任意键继续...");
getch();
}

numsoftest()
{
int n;
clrscr();
do{
  printf("\n请输入题数(10～20):");
  scanf("%d",&n);
  }while (n<10||n>20);
return n;
}

practise()
{
int ts,i,m,n,s;
ts=numsoftest();
randomize();
for (i=1;i<=ts;i++){
  do {
    m=num();n=num();
    }while ((m+n)>9);
  printf("%d) %d+%d=",i,m,n);
  scanf("%d",&s);
  if (s==m+n) right();
  else wrong();
  }
printf("按任意键继续...");
getch();
}

num()
{
return random(9);
}

right()
{
printf("正确\n");
}

wrong()
{
printf("错误\n");
}