c - 加号未被读取

Question

出于某种原因，我的程序根本不读取加号，如果我这样做也没关系:

#include <stdio.h>
#include <math.h>

int main (){

 int nextInt,number,boolean;
 char sign;
 scanf("%d", &number);
 boolean = 1;

 while(boolean == 1){ //+43 *42 %37
   scanf("%c %d", &sign, &nextInt);

   switch ((int)sign){
     case 43:{ number += nextInt; printf("+= %d\n", number); break;}
     case 42:{ number *= nextInt; printf("*= %d\n", number); break;}
     case 37:{ printf("mod %d\n", number);
                number %= nextInt;
                boolean = 0; break;}
   }
 }

 printf("%d", number);
 return 0;
}

或者用符号 switch (sign) 来切换 ascii。我现在有点不知道问题的根源是什么。我做错了什么？

编辑:粘贴整个代码

Answer 1

自 1806 % 37 = 30 起，您可以验证以下内容是否有效。

#include <stdio.h>

int main (){

  int nextInt=0;
  int number=0;
  int boolean;
  char sign;
  boolean = 1;

  while(boolean == 1){ //+43 *42 %37
    scanf(" %c %d", &sign, &nextInt);

    switch (sign){
      case '+':{ number += nextInt; printf("+= %d\n", number); break;}
      case '*':{ number *= nextInt; printf("*= %d\n", number); break;}
      case '%':{ printf("mod %d\n", number);
        number %= nextInt;
        boolean = 0; break;}
    }
  }

  printf("%d", number);
  return 0;
}

你的程序没有读取 plus 的原因是它不在循环中。您可以验证该程序是否有效:

+43
+= 43
*42
*= 1806
%37
mod 1806
30
Process finished with exit code 0