C代码给出错误答案，但Java代码给出正确的spoj答案

Question

I am solving following problem on SPOJ.It is simple insertion sort algorithm. My java code works but C code is giving wrong answer. what wrong i am doing?

Please help and thanks lot......:)

link of problem statement

java code

public class Main {

   public static void main(String[] args) throws NumberFormatException, IOException {
      BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
      int t = Integer.parseInt(br.readLine());
      while (t > 0) {
         int n = Integer.parseInt(br.readLine());
         String str = br.readLine();
         String arr[] = str.split(" ");
         int inputArr[] = new int[n];
         for (int i = 0; i < n; i++) {
            inputArr[i] = Integer.parseInt(arr[i]);
         }
         int key = 0;
         int count = 0;
         for( int i = 1; i < n; i++ ) {
            key = inputArr[i];
            int j = i - 1;
            while (j >= 0 && inputArr[j] > key) {
               inputArr[j + 1] = inputArr[j];
               j = j - 1;
               count++;
            }
            inputArr[j + 1] = key;
         }
         System.out.println(count);
         t--;
      }
   }
}

C code

#include<stdio.h>
int main() {
   int t=0;
   scanf("%d",&t);
   while( t > 0 ) {
      int n=0;
      scanf("%d",&n);
      int arr[n];
      int key=0;
      for(int i=0; i<n; i++) {
         scanf("%d",&arr[i]);
      }
      int count=0;
      int j=0;
      for(int i=1; i<n; i++) {
         key = arr[i];
         j   = i - 1;
         while(j>=0&&arr[j]>key) {
            arr[j+1]=arr[j];
            count++;
            j = j-1;
         }
         arr[j+1]=key;
      }
      printf("%d",count);
      t--;
   }
   return 0;
}

Answer 1

Your code, simplified, without any user input:

In C:

#include <stdio.h>

int insertion_sort() {
   int arr[] = { 1, 1, 1, 2, 2 };
   /*int arr[] = { 2, 1, 3, 1, 2 };*/
   int n     = sizeof(arr)/sizeof(arr[0]);
   int count = 0;
   for(int i = 1; i < n; i++ ) {
      int key = arr[i];
      int j   = i - 1;
      while(( j >= 0 ) && ( arr[j] > key )) {
         arr[j+1] = arr[j];
         count++;
         j = j-1;
      }
      arr[j+1]=key;
   }
   for( int i = 0; i < n; i++ ) {
      printf( "%d,",arr[i]);
   }
   printf( "\n" );
   printf( "count: %d\n",count );
   return 0;
}

In Java:

public class InsertionSort {

   public static void main( String[] args ) throws Exception {
      //final int inputArr[] = { 1, 1, 1, 2, 2 };
      final int inputArr[] = { 2, 1, 3, 1, 2 };
      final int n = inputArr.length;
      int count = 0;
      for( int i = 1; i < n; i++ ) {
         final int key = inputArr[i];
         int j   = i - 1;
         while(( j >= 0 ) && ( inputArr[j] > key )) {
            inputArr[j + 1] = inputArr[j];
            j = j - 1;
            count++;
         }
         inputArr[j + 1] = key;
      }
      System.out.println( Arrays.toString( inputArr ));
      System.out.println( "count: " + count );
   }
}

C Execution trace:

1,1,1,2,2,
count: 0

2,1,3,1,2,
count: 4

Java Execution trace:

[1, 1, 1, 2, 2]
count: 0

[2, 1, 3, 1, 2]
count: 4

Where is the differences?

EDIT

Your code isn't ANSI C:

gcc -ansi -c insertion_sort.c 
insertion_sort.c: In function ‘insertion_sort’:
insertion_sort.c:34:7: error: ‘for’ loop initial declarations are only allowed in C99 or C11 mode
       for(int i=0; i<n; i++) {
       ^
insertion_sort.c:34:7: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code
insertion_sort.c:39:15: error: redefinition of ‘i’
       for(int i=1; i<n; i++) {
               ^
insertion_sort.c:34:15: note: previous definition of ‘i’ was here
       for(int i=0; i<n; i++) {
               ^
insertion_sort.c:39:7: error: ‘for’ loop initial declarations are only allowed in C99 or C11 mode
       for(int i=1; i<n; i++) {
       ^

Answer 2

The code itself is correct, but your output is wrong. Expected output format is a number followed by newline. Your Java code uses println which automatically inserts newline. Your C code lacks \\n . printf("%d\\n", count); is what you should use.

Answer 3

Your solution seems to be correct!

When you upload the solution, select the correct version of C compiler. You are using C99 or next, i think.. so try to use it! C99