Language: C++

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
 
int stack[1000];
int kazu;
 
void push(int j){
  stack[++kazu] = j;
}
int pop(){
  kazu--;
  return stack[kazu+1];
}
 
int main(){
  int l,n;
  kazu = 0;
  char s[100];
  while( scanf("%s", s)!=EOF){
    if(s[0] == '+'){
      l =pop();
      n =pop();
      push(l+n);
    }
    else if(s[0]=='-'){
      n = pop();
      l = pop();
      push(l-n);
    }
    else if(s[0]=='*'){
      l = pop();
      n = pop();
      push(l*n);
    }
    else{
      push(atoi(s));
    }
  }
  printf("%d\n", pop());
  return 0;
}


Compiler output:
a.cc:4:1: error: extended character   is not valid in an identifier
    4 |  
      | ^
a.cc:7:1: error: extended character   is not valid in an identifier
    7 |  
      | ^
a.cc:9:1: error: extended character   is not valid in an identifier
    9 |   stack[++kazu] = j;
      | ^
a.cc:9:1: error: extended character   is not valid in an identifier
a.cc:12:1: error: extended character   is not valid in an identifier
   12 |   kazu--;
      | ^
a.cc:12:1: error: extended character   is not valid in an identifier
a.cc:13:1: error: extended character   is not valid in an identifier
   13 |   return stack[kazu+1];
      | ^
a.cc:13:1: error: extended character   is not valid in an identifier
a.cc:15:1: error: extended character   is not valid in an identifier
   15 |  
      | ^
a.cc:17:1: error: extended character   is not valid in an identifier
   17 |   int l,n;
      | ^
a.cc:17:1: error: extended character   is not valid in an identifier
a.cc:18:1: error: extended character   is not valid in an identifier
   18 |   kazu = 0;
      | ^
a.cc:18:1: error: extended character   is not valid in an identifier
a.cc:19:1: error: extended character   is not valid in an identifier
   19 |   char s[100];
      | ^
a.cc:19:1: error: extended character   is not valid in an identifier
a.cc:20:1: error: extended character   is not valid in an identifier
   20 |   while( scanf("%s", s)!=EOF){
      | ^
a.cc:20:1: error: extended character   is not valid in an identifier
a.cc:21:1: error: extended character   is not valid in an identifier
   21 |     if(s[0] == '+'){
      | ^
a.cc:21:1: error: extended character   is not valid in an identifier
a.cc:21:1: error: extended character   is not valid in an identifier
a.cc:21:1: error: extended character   is not valid in an identifier
a.cc:22:1: error: extended character   is not valid in an identifier
   22 |       l =pop();
      | ^
a.cc:22:1: error: extended character   is not valid in an identifier
a.cc:22:1: error: extended character   is not valid in an identifier
a.cc:22:1: error: extended character   is not valid in an identifier
a.cc:22:1: error: extended character   is not valid in an identifier
a.cc:22:1: error: extended character   is not valid in an identifier
a.cc:23:1: error: extended character   is not valid in an identifier
   23 |       n =pop();
      | ^
a.cc:23:1: error: extended character   is not valid in an identifier
a.cc:23:1: error: extended character   is not valid in an identifier
a.cc:23:1: error: extended character   is not valid in an identifier
a.cc:23:1: error: extended character   is not valid in an identifier
a.cc:23:1: error: extended character   is not valid in an identifier
a.cc:24:1: error: extended character   is not valid in an identifier
   24 |       push(l+n);
      | ^
a.cc:24:1: error: extended character   is not valid in an identifier
a.cc:24:1: error: extended character   is not valid in an identifier
a.cc:24:1: error: extended character   is not valid in an identifier
a.cc:24:1: error: extended character   is not valid in an identifier
a.cc:24:1: error: extended character   is not valid in an identifier
a.cc:25:1: error: extended character   is not valid in an identifier
   25 |     }
      | ^
a.cc:25:1: error: extended character   is not valid in an identifier
a.cc:25:1: error: extended character   is not valid in an identifier
a.cc:25:1: error: extended character   is not valid in an identifier
a.cc:26:1: error: extended character   is not valid in an identifier
   26 |     else if(s[0]=='-'){
      | ^
a.cc:26:1: error: extended character   is not valid in an identifier
a.cc:26:1: error: extended character   is not valid in an identifier
a.cc:26:1: error: extended character   is not valid in an identifier
a.cc:27:1: error: extended character   is not valid in an identifier
   27 |       n = pop();
      | ^
a.cc:27:1: error: extended character   is not valid in an identifier
a.cc:27:1: error: extended character   is not valid in an identifier
a.cc:27:1: error: extended character   is not valid in an identifier
a.cc:27:1: error: extended character   is not valid in an identifier
a.cc:27:1: error: extended character   is not valid in an identifier
a.cc:28:1: error: extended character   is not valid in an identifier
   28 |       l = pop();
      | ^
a.cc:28:1: error: extended character   is not valid in an identifier
a.cc:28:1: error: extended character   is not valid in an identifier
a.cc:28:1: error: extended character   is not valid in an identifier
a.cc:28:1: error: extended character   is not valid in an identifier
a.cc:28:1: error: extended character   is not valid in an identifier
a.cc:29:1: error: extended character   is not valid in an identifier
   29 |       push(l-n);
      | ^
a.cc:29:1: error: extended character   is not valid in an identifier
a.cc:29:1: error: extended character   is not valid in an identifier
a.cc:29:1: error: extended character   is not valid in an identifier
a.cc:29:1: error: extended character   is not valid in an identifier
a.cc:29:1: error: extended character   is not valid in an identifier
a.cc:30:1: error: extended character   is not valid in an identifier
   30 |     }
      | ^
a.cc:30:1: error: extended character   is not valid in an identifier
a.cc:30:1: error: extended character   is not valid in an identifier
a.cc:30:1: error: extended character   is not valid in an identifier
a.cc:31:1: error: extended character   is not valid in an identifier
   31 |     else if(s[0]=='*'){
      | ^
a.cc:31:1: error: extended character   is not valid in an identifier
a.cc:31:1: error: extended character   is not valid in an identifier
a.cc:31:1: error: extended character   is not valid in an identifier
a.cc:32:1: error: extended character   is not valid in an identifier
   32 |       l = pop();
      | ^
a.cc:32:1: error: extended character   is not valid in an identifier
a.cc:32:1: error: extended character   is not valid in an identifier
a.cc:32:1: error: extended character   is not valid in an identifier
a.cc:32:1: error: extended character   is not valid in an identifier
a.cc:32:1: error: extended character   is not valid in an identifier
a.cc:33:1: error: extended character   is not valid in an identifier
   33 |       n = pop();
      | ^
a.cc:33:1: error: extended character   is not valid in an identifier
a.cc:33:1: error: extended character   is not valid in an identifier
a.cc:33:1: error: extended character   is not valid in an identifier
a.cc:33:1: error: extended character   is not valid in an identifier
a.cc:33:1: error: extended character   is not valid in an identifier
a.cc:34:1: error: extended character   is not valid in an identifier
   34 |       push(l*n);
      | ^
a.cc:34:1: error: extended character   is not valid in an identifier
a.cc:34:1: error: extended character   is not valid in an identifier
a.cc:34:1: error: extended character   is not valid in an identifier
a.cc:34:1: error: extended character   is not valid in an identifier
a.cc:34:1: error: extended character   is not valid in an identifier
a.cc:35:1: error: extended character   is not valid in an identifier
   35 |     }
      | ^
a.cc:35:1: error: extended character   is not valid in an identifier
a.cc:35:1: error: extended character   is not valid in an identifier
a.cc:35:1: error: extended character   is not valid in an identifier
a.cc:36:1: error: extended character   is not valid in an identifier
   36 |     else{
      | ^
a.cc:36:1: error: extended character   is not valid in an identifier
a.cc:36:1: error: extended character   is not valid in an identifier
a.cc:36:1: error: extended character   is not valid in an identifier
a.cc:37:1: error: extended character   is not valid in an identifier
   37 |       push(atoi(s));
      | ^
a.cc:37:1: error: extended character   is not valid in an identifier
a.cc:37:1: error: extended character   is not valid in an identifier
a.cc:37:1: error: extended character   is not valid in an identifier
a.cc:37:1: error: extended character   is not valid in an identifier
a.cc:37:1: error: extended character   is not valid in an identifier
a.cc:38:1: error: extended character   is not valid in an identifier
   38 |     }
      | ^
a.cc:38:1: error: extended character   is not valid in an identifier
a.cc:38:1: error: extended character   is not valid in an identifier
a.cc:38:1: error: extended character   is not valid in an identifier
a.cc:39:1: error: extended character   is not valid in an identifier
   39 |   }
      | ^
a.cc:39:1: error: extended character   is not valid in an identifier
a.cc:40:1: error: extended character   is not valid in an identifier
   40 |   printf("%d\n", pop());
      | ^
a.cc:40:1: error: extended character   is not valid in an identifier
a.cc:41:1: error: extended character   is not valid in an identifier
   41 |   return 0;
      | ^
a.cc:41:1: error: extended character   is not valid in an identifier
a.cc:4:1: error: '\U000000a0' does not name a type
    4 |  
      | ^
a.cc:7:1: error: '\U000000a0' does not name a type
    7 |  
      | ^
a.cc: In function 'int pop()':
a.cc:12:1: error: '\U000000a0\U000000a0kazu' was not declared in this scope
   12 |   kazu--;
      | ^~~~~~
a.cc:13:1: error: '\U000000a0\U000000a0return' was not declared in this scope
   13 |   return stack[kazu+1];
      | ^~~~~~~~
a.cc:14:1: warning: no return statement in function returning non-void [-Wreturn-type]
   14 | }
      | ^
a.cc: At global scope:
a.cc:15:1: error: '\U000000a0' does not name a type
   15 |  
      | ^