array-10.c

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

void main(void)
{
    int Lower[5][5] = { 3, 0, 0, 0, 0,
                        7, 5, 0, 0, 0,
                        6, 4, 5, 0, 0,
                        8, 3, 2, 1, 0,
                        9, 1, 6, 4, 9 };
    int RowMajor[15];
    int Index;
    int i, j;

    printf("Two dimensional Lower triangular array:\n");
    for(i = 0; i < 5; i++)
    {
        for(j = 0; j < 5; j++)
            printf("%3d", Lower[i][j]);
        printf("\n");
    }

    for(i = 0; i < 5; i++)
       for(j = 0; j < 5; j++)
           if(i >= j)
           {
               Index = i * (i + 1) / 2 + j;
               RowMajor[Index] = Lower[i][j];
           }
        printf("\n");

    printf("Row Major one dimensional array:\n");
    for(i = 0; i < 15; i++)
        printf("%3d", RowMajor[i]);
    printf("\n");
}