Banker_Algorithm_Greedy_Approach

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

void final_output(int k[][10], int n, int p)
{
	int i, j;
	for (i = 0; i < n; i++)
	{
		printf("\n");
		for (j = 0; j < p; j++)
		{
			printf("%d\t", k[i][j]);
		}
	}
}

void Banker(int A[][10], int N[][10],
	int M[10][10], int W[1][10], int *n, int *m)
{
	int i, j;
	printf("\n Enter total number of processes : ");
	scanf("%d", n);
	printf("\n Enter total number of resources : ");
	scanf("%d", m);
	for (i = 0; i<*n; i++)
	{
		printf("\n Process %d\n", i + 1);
		for (j = 0; j<*m; j++)
		{
			printf(" Allocation for resource %d : ", j + 1);
			scanf("%d", &A[i][j]);
			printf(" Maximum for resource %d : ", j + 1);
			scanf("%d", &M[i][j]);
		}
	}

	printf("\n Available resources : \n");
	for (i = 0; i<*m; i++)
	{
		printf(" Resource %d : ", i + 1);
		scanf("%d", &W[0][i]);
	}

	for (i = 0; i<*n; i++)
		for (j = 0; j<*m; j++)
			N[i][j] = M[i][j] - A[i][j];
	printf("\n -----Allocation Matrix-----");
	final_output(A, *n, *m);
	printf("\n -----Maximum Requirement Matrix-----");
	final_output(M, *n, *m);
	printf("\n -----Need Matrix-----");
	final_output(N, *n, *m);
}

int safety(int A[][10], int N[][10],
	int B[1][10], int n, int m, int a[])
{
	int i, j, k, x = 0, f1 = 0, f2 = 0;
	int F[10], W[1][10];
	for (i = 0; i < n; i++)
		F[i] = 0;
	for (i = 0; i < m; i++)
		W[0][i] = B[0][i];
	for (k = 0; k < n; k++)
	{
		for (i = 0; i < n; i++)
		{
			if (F[i] == 0)
			{
				f2 = 0;
				for (j = 0; j < m; j++)
				{
					if (N[i][j] > W[0][j])
						f2 = 1;
				}

				if (f2 == 0 && F[i] == 0)
				{
					for (j = 0; j < m; j++)
						W[0][j] += A[i][j];
					F[i] = 1;
					f1++;
					a[x++] = i;
				}
			}
		}

		if (f1 == n)
			return 1;
	}

	return 0;
}

void request(int A[10][10], int N[10][10], int B[10][10], int pid, int K)
{
	int rmat[1][10];
	int i;
	printf("\n Enter additional request : \n");
	for (i = 0; i < K; i++)
	{
		printf(" Request for resource %d : ", i + 1);
		scanf("%d", &rmat[0][i]);
	}

	for (i = 0; i < K; i++)
		if (rmat[0][i] > N[pid][i])
		{
			printf("\n ***Error encountered***\n");
			exit(0);
		}

	for (i = 0; i < K; i++)
		if (rmat[0][i] > B[0][i])
		{
			printf("\n ***Resources unavailable**\n");
			exit(0);
		}

	for (i = 0; i < K; i++)
	{
		B[0][i] -= rmat[0][i];
		A[pid][i] += rmat[0][i];
		N[pid][i] -= rmat[0][i];
	}
}

int banker(int A[][10], int N[][10],
	int W[1][10], int n, int m)
{
	int j, i, a[10];
	j = safety(A, N, W, n, m, a);
	if (j != 0)
	{
		printf("\n\n");
		printf("\n A safety sequence has been "
			"detected.\n");
		for (i = 0; i < n; i++)
			printf(" P%d ", a[i]);
		printf("\n");
		return 1;
	}
	else
	{
		printf("\n Deadlock has occured.\n");
		return 0;
	}
}

int main()
{
	int All[10][10], Max[10][10], Need[10][10], W[1][10];
	int n, m, pid, c, r;
	printf("\n -----BANKER'S ALGORITHM-----\n");
	Banker(All, Need, Max, W, &n, &m);
	r = banker(All, Need, W, n, m);
	if (r != 0)
	{
		printf("\n Do you want to continue?");
		scanf("%d", &c);
		if (c == 1)
		{
			printf("\n Enter process number : ");
			scanf("%d", &pid);
			request(All, Need, W, pid - 1, m);
			r = banker(All, Need, W, n, m);
			if (r == 0)
			{
				exit(0);
			}
		}
	}
	else
		exit(0);
	return 0;
}