My code works fine with the sample inputs. But whenever I submit the code to code marshal, it gets unaccepted.

r_pyramid.c

#include <stdlib.h>
#include <stdio.h>

int main()
{
	int i, j, t, k,m,n;

	scanf("%d", &t);

	for(i=1; i<=t; i++)
	{
		scanf("%d", &k);
		for(j = 0; j< k; j++ )
		{
			for(m = k-1; m>j; m--)
			{
				printf(" ");
			}

			for(n=0; n<=j*2; n++)
			{
				printf("*");
			}
			printf(" \n");
		}
			printf("\n");
	}
	return 0;
}

s_wave.c

#include <stdlib.h>
#include <stdio.h>

int main()
{
	int i, j, n, m;
	unsigned short int t,k;

	scanf("%hu", &t);

	for(i=1; i<=t; i++)
	{
		scanf("%hu", &k);
		for(j = 0; j< k; j++ )
		{
			for(m = k-1; m>j; m--)
			{
				printf(" ");
			}

			for(n=0; n<=j*2; n++)
			{
				printf("*");
			}
			printf("\n");
		}
		for(j = k-2; j>=0; j-- )
		{
			for(m = k-1; m>j; m--)
			{
				printf(" ");
			}

			for(n=0; n<=j*2; n++)
			{
				printf("*");
			}
			printf("\n");
		}

			printf("\n");
	}
	return 0;
}

u_diff_arr.c

#include <stdlib.h>
#include <stdio.h>

int main()
{
	int i,j,k,l,N,t, temp;


	scanf("%d", &t);
	for(l=0; l<t;l++)
	{
		scanf("%d",&N);
		int n_array[N];
		for(i=0; i<N; i++)
		{
			scanf("%d", &n_array[i]);
		}

		j = i-1;
		i=0;

		while(i<j)
		{
			temp = n_array[i];
			n_array[i] = n_array[j];
			n_array[j] = temp;
			j--;
			i++;
		}
		printf("%d", n_array[0]);

		for(k = 1; k<N; k++)
		{
			printf(" %d", n_array[k]);
		}

		printf("\n");
	}


}