Language: C

#include<stdio.h>
#define MAX 100005
#define NIL -1 
struct Node{ int p, l, r;};
struct Node T[MAX];
 
void inorder(int u){
    if(u != NIL) {  
    if(T[u].l != NIL) inorder(T[u].l); 
printf(" %d",T[u].l);    
if(T[u].r != NIL) inorder(T[u].r);  
    }
}
void preorder(int u){
    if(u != NIL) {  
    printf(" %d",T[u].l);   
if(T[u].l != NIL) preorder(T[u].l);
if(T[u].r != NIL)
preorder(T[u].l); 
 
    }
}
 
void postorder(int u){
    if(u != NIL){
        if(T[u].l != NIL) postorder(T[u].l);
        if(T[u].l != NIL)
        postorder(T[u].r);
        printf(" %d",T[u].l);
    }
}
 
int main(){
    int i, v,n;     
    scanf("%d", &n);
    for ( i = 0; i < n; i++ ) {
        T[i].p = T[i].l = T[i].r = NIL; 
        } 
        for ( i = 0; i < n; i++ ){ 
            scanf("%d",&v);
            scanf("%d %d",&T[v].l,&T[v].r);    
            T[T[v].l].p = v;
            T[T[v].r].p = v; 
            } 
            
            
            printf("Preorder\n");
            for ( i = 0; i < n; i++ ){
           preorder(i);
            }
            printf("\nInorder\n");
            for(i=0; i<n; i++){
                inorder(i);
            }
            printf("\nPostorder\n");
            for(i=0; i<n; i++){
           postorder(i);
            }
            
            return 0;
            
}

Compiler output:
main.c:1:1: error: stray '\1' in program
    1 | <U+0001><U+0001><U+0001><U+0001><U+0001><U+0001>#include<stdio.h>
      | ^~~~~~~~
main.c:1:2: error: stray '\1' in program
    1 | <U+0001><U+0001><U+0001><U+0001><U+0001><U+0001>#include<stdio.h>
      |         ^~~~~~~~
main.c:1:3: error: stray '\1' in program
    1 | <U+0001><U+0001><U+0001><U+0001><U+0001><U+0001>#include<stdio.h>
      |                 ^~~~~~~~
main.c:1:4: error: stray '\1' in program
    1 | <U+0001><U+0001><U+0001><U+0001><U+0001><U+0001>#include<stdio.h>
      |                         ^~~~~~~~
main.c:1:5: error: stray '\1' in program
    1 | <U+0001><U+0001><U+0001><U+0001><U+0001><U+0001>#include<stdio.h>
      |                                 ^~~~~~~~
main.c:1:6: error: stray '\1' in program
    1 | <U+0001><U+0001><U+0001><U+0001><U+0001><U+0001>#include<stdio.h>
      |                                         ^~~~~~~~
main.c:1:7: error: stray '#' in program
    1 | #include<stdio.h>
      |       ^
main.c:1:15: error: expected '=', ',', ';', 'asm' or '__attribute__' before '<' token
    1 | #include<stdio.h>
      |               ^
main.c:5:13: error: array type has incomplete element type 'struct Node'
    5 | struct Node T[MAX];
      |             ^
main.c: In function 'inorder':
main.c:10:1: error: implicit declaration of function 'printf' [-Wimplicit-function-declaration]
   10 | printf(" %d",T[u].l);
      | ^~~~~~
main.c:1:1: note: include '<stdio.h>' or provide a declaration of 'printf'
  +++ |+#include <stdio.h>
    1 | #include<stdio.h>
main.c:10:1: warning: incompatible implicit declaration of built-in function 'printf' [-Wbuiltin-declaration-mismatch]
   10 | printf(" %d",T[u].l);
      | ^~~~~~
main.c:10:1: note: include '<stdio.h>' or provide a declaration of 'printf'
main.c: In function 'preorder':
main.c:16:5: warning: incompatible implicit declaration of built-in function 'printf' [-Wbuiltin-declaration-mismatch]
   16 |     printf(" %d",T[u].l);
      |     ^~~~~~
main.c:16:5: note: include '<stdio.h>' or provide a declaration of 'printf'
main.c: In function 'postorder':
main.c:29:9: warning: incompatible implicit declaration of built-in function 'printf' [-Wbuiltin-declaration-mismatch]
   29 |         printf(" %d",T[u].l);
      |         ^~~~~~
main.c:29:9: note: include '<stdio.h>' or provide a declaration of 'printf'
main.c: In function 'main':
main.c:35:5: error: implicit declaration of function 'scanf' [-Wimplicit-function-declaration]
   35 |     scanf("%d", &n);
      |     ^~~~~
main.c:35:5: note: include '<stdio.h>' or provide a declaration of 'scanf'
main.c:35:5: warning: incompatible implicit declaration of built-in function 'scanf' [-Wbuiltin-declaration-mismatch]
main.c:35:5: note: include '<stdio.h>' or provide a declaration of 'scanf'
main.c:47:13: warning: incompatible implicit declaration of built-in function 'printf' [-Wbuiltin-declaration-mismatch]
   47 |             printf("Preorder\n");
      |             ^~~~~~
main.c:47:13: note: include '<stdio.h>' or provide a declaration of 'printf'