“我遇到的实际问题是它在给出问题数量后停止运行。我已将“%d%”更正为“%d”，但仍然存在该问题”
我目前正在做一个小型数学游戏的项目。我需要提示一个难度（简单、困难或退出）级别，然后是一个类别（加法、减法、乘法和除法。我的菜单正常工作，但我似乎无法得到以下任何内容
printf (" How many questions would you like to attempt?\n");
scanf ("%d%", &numofquestions);
去工作。谁能告诉我我做错了什么？以下是我到目前为止的完整代码，那里有一些不必要的项目，但据我所知，它们不是问题。
/* Program Description Goes Here */
#include <stdio.h>
#include <stdlib.h>
/* function main begins program execution */
int main( void )
{
/* Main Code Area For Program */
int difficulty = -1;
int category = 0;
int numofquestions;
int ca = 0; /* Correct Answer */
int cc; /* Correcnt Counter */
int ran1;
int ran2;
int random1 = 0;
int random2 = 0;
int usera;
int i;
/* Welcome mesage */
srand ( time (NULL));
printf ( "Welcome to the math challenge.\n");
while ( difficulty != 1 && difficulty != 2 && difficulty !=0){
printf ("Select 1 for Easy\n");
printf ("Select 2 for Hard\n");
printf ("Select 0 to Quit\n");
scanf ( "%d", &difficulty);
}
while ( category != 1 && category != 2 && category != 3 && category != 4){
category = getchar();
switch (category){
case 'A':
case 'a':
category = 1;
break;
case 'S':
case 's':
category = 2;
break;
case 'M':
case 'm':
category = 3;
break;
case 'D':
case 'd':
category = 4;
break;
case '/n':
case '/t':
case ' ':
break;
default:
printf ("Enter A for Addition\n");
printf ("Enter S for Subtraction\n");
printf ("Enter M for Multiplication\n");
printf ("Enter D for Division\n");
}
}
printf (" How many questions would you like to attempt?\n");
scanf ("%d%", &numofquestions);
for (i = numofquestions; i<=0; --i){/* start for */
if ( difficulty == 1){ /* start if */
random1 = (rand () % 10);
random2 = (rand () % 10);
}/* end if */
if ( category == 1){/* start if */
printf ( "%d + %d = ?" , random1 , random2 );
ca = random1 + random2;
printf ( "Your response\n");
scanf ( "%d", &usera);
}/* end if */
if ( usera == ca ){ /* start if */
printf (" %d\n ", ca);
}/* end if */
/* end for */}
return 0; /* indicate that program ended successfully */
/* end function main */
}