#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#define DIMSIZE 5

void fillTriangularMatrixRandom(int A[][DIMSIZE]);
void display2DMatrix(int A[][DIMSIZE]);
void transformTriangular(int A[][DIMSIZE], int B[]);
void setValue(int i, int j, int val, int B[]);
void display1DMatrix(int B[], int length);
void display1DTriangularTo2DMatrix(int B[]);


main()
{
	int A[DIMSIZE][DIMSIZE];
	int B[DIMSIZE*(DIMSIZE+1)/2]; //yparxoyn N(N+1)/2 stoixeia poy briskontai 
								  //apo th diagonio kai kato
	int index,value;
	srand(time(0));
	printf("PINAKAS A");
	fillTriangularMatrixRandom(A);
	printf("\nArxikopoihsh me random times oloklhrothike\n");
	printf("\nPINAKAS A\n");
	printf("Ta stoixeia tou pinaka einai:\n");
	display2DMatrix(A);
	transformTriangular(A,B);
	printf("\nPINAKAS B monodiastatos");
	display1DMatrix(B, DIMSIZE*(DIMSIZE+1)/2);
	printf("\n\nPINAKAS B antistoixos kato trigonikos");
	display1DTriangularTo2DMatrix(B);
	do {//to index prepei na einai entos orion toy B[]
		printf ("\nDose th thesh toy stoixeioy sto monodiastato pinaka poy thes na allakseis: ");
		scanf("%d", &index);
		printf ("\nDose thn timh poy thes na exei: ");
		scanf("%d", &value);
	}
	while (index<0 || index>=DIMSIZE*(DIMSIZE+1)/2);
	B[index]=value; //allazoyme to stoixeio ston pinaka B 
	printf("\nPINAKAS B monodiastatos");
	display1DMatrix(B, DIMSIZE*(DIMSIZE+1)/2);
	printf("\n\nPINAKAS B antistoixos kato trigonikos");
	display1DTriangularTo2DMatrix(B);

}

void fillTriangularMatrixRandom(int A[][DIMSIZE])
{
	int i,j;
	for(i=0; i<DIMSIZE; i++)
		for(j=0; j<DIMSIZE; j++)
			if(i>=j)
				A[i][j] = rand()%10;
			else A[i][j] = 0;
}

void display2DMatrix(int A[][DIMSIZE])
{
	int i,j;

	for(i=0; i<DIMSIZE; i++){
		for(j=0; j<DIMSIZE; j++)
			printf("%d ",A[i][j]);
		printf("\n");
	}
}

void transformTriangular(int A[][DIMSIZE], int B[])
{
	int i,j;

	for(i=0; i<DIMSIZE; i++)
		for(j=0; j<DIMSIZE; j++)
			if(i>=j)
			setValue(i,j,A[i][j],B);
}

void setValue(int i, int j, int val, int B[])
{
	B[i*(i+1)/2+j] = val;
}

void display1DMatrix(int B[], int length)
{
	for(length=0; length<=DIMSIZE*(DIMSIZE+1)/2; length++)
		printf("%d ",B[length]);
}

void display1DTriangularTo2DMatrix(int B[])
{
	int i,j;

	for(i=0; i<DIMSIZE; i++){
		printf("\n");
		for(j=0; j<DIMSIZE; j++)
			if(i>=j) printf("%d ",B[i*(i+1)/2+j]);
			else printf("%d ",0);
	}
}