fork(2) download
copy 
  1. #include <stdlib.h>
  2. #include <stdio.h>
  3. int postf(char*);
  4. int priority(char);
  5.  
  6. int main()
  7. {
  8.     char in[100];
  9.     scanf("%s",in);
  10.     postf(in);
  11.  
  12. }
  13. int postf(char* fix) {
  14.     int i = 0, top = 0;
  15.     char stack[100]={'\0'};
  16.     char op;
  17.  
  18.     while(1) {
  19.  
  20.         op=fix[i];
  21.  
  22.         switch(op) {
  23.             case '\0':
  24.  
  25.                 while(top > 0) {
  26.                     printf("%c", stack[top]);
  27.                     top--;
  28.                 }
  29.  
  30.                 printf("\n");
  31.                 return 0;
  32.  
  33.             case '(':
  34.                 if(top<(sizeof(stack) / sizeof(char))) {
  35.                     top++;
  36.                     stack[top]=op;
  37.                 }
  38.                 break;
  39.             case '+':
  40.             case '-':
  41.             case '*':
  42.             case '/':
  43.                 while(priority(stack[top]) >= priority(op)) {
  44.                     printf("%c", stack[top]);
  45.                     top--;
  46.                 }
  47.  
  48.                 if(top < (sizeof(stack) / sizeof(char))) {
  49.                     top++;
  50.                     stack[top] = op;
  51.                 }
  52.                 break;
  53.  
  54.             case ')':
  55.                 while(stack[top] != '(') {
  56.                     printf("%c",stack[top]);
  57.                     top--;
  58.                 }
  59.                 top--;
  60.                 break;
  61.             default:
  62.                 printf("%c",op);
  63.  
  64.  
  65.                 break;
  66.  
  67. }
  68.  
  69.         i++;
  70.  
  71.  
  72.     }
  73.  
  74.  
  75. }
  76.  
  77. int priority(char op) {
  78.     int a;
  79.  
  80.     switch(op) {
  81.  
  82.         case '+':
  83.         case '-':
  84.             a = 1;
  85.             break;
  86.  
  87.         case '*':
  88.         case '/':
  89.             a = 2;
  90.             break;
  91.  
  92.         default:
  93.             a = 0;
  94.             break;
  95.     }
  96.  
  97.     return a;
  98. }
  99.  
Success #stdin #stdout 0s 2056KB
comments (?)
stdin
copy 
12+12+13
A+B
stdout
copy 
1212+13+
https://ideone.com/YedF6N
language:
C (gcc 8.3)
created:
10 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!