CODES/graph_col.cpp at main · ananya07105/CODES · GitHub

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#include <stdbool.h>
#include <stdio.h>
#define V 4
void printSolution(int color[]);
bool isSafe(bool graph[V][V], int color[])
{
	for (int i = 0; i < V; i++)
		for (int j = i + 1; j < V; j++)
			if (graph[i][j] && color[j] == color[i])
				return false;
	return true;
}
bool graphColoring(bool graph[V][V], int m, int i,
				int color[V])
{
	if (i == V) {
		if (isSafe(graph, color)) {
			printSolution(color);
			return true;
		}
		return false;
	}
	for (int j = 1; j <= m; j++) {
		color[i] = j;
		if (graphColoring(graph, m, i + 1, color))
			return true;

		color[i] = 0;
	}

	return false;
}
void printSolution(int color[])
{
	printf("Solution Exists:"
		" Following are the assigned colors \n");
	for (int i = 0; i < V; i++)
		printf(" %d ", color[i]);
	printf("\n");
}
int main()
{
	bool graph[V][V] = {
		{ 0, 1, 1, 1 },
		{ 1, 0, 1, 0 },
		{ 1, 1, 0, 1 },
		{ 1, 0, 1, 0 },
	};
	int m = 3;
	int color[V];
	for (int i = 0; i < V; i++)
		color[i] = 0;

	if (!graphColoring(graph, m, 0, color))
		printf("Solution does not exist");

	return 0;
}