import java.io.*;
import java.lang.*;
import java.util.*;
class Allpairshortestpath {
final static int INF = 99999, V = 4;
void floydWarshall(int dist[][])
{
int i, j, k;
for (k = 0; k < V; k++) {
for (i = 0; i < V; i++) {
for (j = 0; j < V; j++) {
if (dist[i][k] + dist[k][j]< dist[i][j])dist[i][j]= dist[i][k] + dist[k][j];
}
}
}
printSolution(dist);
}
void printSolution(int dist[][])
{
System.out.println(
"The following matrix shows the shortest "+ "distances between every pair of vertices");
for (int i = 0; i < V; ++i) {
for (int j = 0; j < V; ++j) {
if (dist[i][j] == INF)
System.out.print("INF ");
else
System.out.print(dist[i][j] + " ");
}
System.out.println();
}
}
public static void main(String[] args)
{
int graph[][] = { { 0, 5, INF, 10 },
{ INF, 0, 3, INF },
{ INF, INF, 0, 1 },
{ INF, INF, INF, 0 } };
Allpairshortestpath a = new Allpairshortestpath();
a.floydWarshall(graph);
}
}
import java.util.*;
public class TSP {
public static void main(String[] args) {
int ans = Integer.MAX_VALUE;
int dp[][] = new int[16][4];
for(int i = 0; i < (1<<n); i++)
{
for(int j = 0; j < n; j++)
{
dp[i][j] = -1;
}}
int shortestDistance = travellingSalesman(1, 0, ans, dp);
System.out.println("The shortest distance to visit all the cities is " + shortestDistance); }
static int[][]distance = {{0, 20, 42, 25},{20, 0 , 30, 34}, {42, 30, 0, 10}, {25, 34, 10, 0}};
static int n = 4;
static int allCityVisited = (1<<n)-1;
public static int travellingSalesman(int bitMask, int currCity, int ans, int[][] dp) {
if(bitMask == allCityVisited) {
return distance[currCity][0];}
if(dp[bitMask][currCity] != -1) {
return dp[bitMask][currCity];
}
for(int city = 0; city < n; city++) {
if((bitMask&(1<<city)) == 0) {
bitMask = bitMask | (1<<city);
int distAns = distance[currCity][city] + travellingSalesman(bitMask, city,ans,dp);
ans = Math.min(ans,distAns); }
}
return dp[bitMask][currCity] = ans;
}
}
import java.lang.*;
class NQueen {
static final int N = 4;
static void printSolution(int board[][])
{
for (int i = 0; i < N; i++) {
for (int j = 0; j < N; j++)
System.out.print(" " + board[i][j]+ " ");
System.out.println();
}
}
static boolean isSafe(int board[][], int row, int col)
{
int i, j;
for (i = 0; i < col; i++)
if (board[row][i] == 1)
return false;
for (i = row, j = col; i >= 0 && j >= 0; i--, j--)
if (board[i][j] == 1)
return false;
for (i = row, j = col; j >= 0 && i < N; i++, j--)
if (board[i][j] == 1)
return false;
return true;
}
public static boolean solveNQueen(int board[][], int col)
{
if (col >= N)
return true;
for (int i = 0; i < N; i++) {
if (isSafe(board, i, col)) {
board[i][col] = 1;
if (solveNQueen(board, col + 1))
return true;
board[i][col] = 0;
}
}
return false;
}
public static void main(String args[])
{
int board[][] = { { 0, 0, 0, 0 },
{ 0, 0, 0, 0 },
{ 0, 0, 0, 0 },
{ 0, 0, 0, 0 } };
if (!solveNQueen(board, 0)) {
System.out.print("Solution does not exist");
return;
}
printSolution(board);
}
}
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.*;
class Sumofsubsets{
public static void findSubsets(Set<List<Integer>> allSubsets, List<Integer> nums, int sum) {
if (nums.size() == 0) {
return;
}
int currentSum = 0;
for (Integer num : nums) {
currentSum += num;
}
if (currentSum == sum) {
allSubsets.add(new ArrayList<>(nums));
}
for (int i = 0; i < nums.size(); i++) {
final List<Integer> subset = new ArrayList<>(nums);
subset.remove(i);
findSubsets(allSubsets, subset, sum);
}
}
public static void main(String[] args) {
final Integer array[];
Scanner s=new Scanner(System.in);
System.out.println("Enter size of the array:");
int n=s.nextInt();
array=new Integer[n];
System.out.println("Enter array elements");
for(int i=0;i<n;i++)
{
array[i]=s.nextInt();
}
System.out.println("Enter Target sum:");
int sum=s.nextInt();
final HashSet<List<Integer>> allSubsets = new HashSet<>();
findSubsets(allSubsets, Arrays.asList(array), sum);
System.out.println("The sum of subsets is:");
System.out.println(allSubsets);
}
}
import java.util.Scanner;
import java.util.Arrays;
public class Ham
{
private int V, pathCount;
private int[] path;
private int[][] graph;
public void findHamiltonianCycle(int[][] g)
{
V = g.length;
path = new int[V];
Arrays.fill(path, -1);
graph = g;
try
{
path[0] = 0;
pathCount = 1;
solve(0);
System.out.println("No solution");
}
catch (Exception e)
{
System.out.println(e.getMessage());
display();
}
}
public void solve(int vertex) throws Exception
{
if (graph[vertex][0] == 1 && pathCount == V)
throw new Exception("Solution found");
if (pathCount == V)
return;
for (int v = 0; v < V; v++)
{
if (graph[vertex][v] == 1 )
{
path[pathCount++] = v;
graph[vertex][v] = 0;
graph[v][vertex] = 0;
if (!isPresent(v))
solve(v);
graph[vertex][v] = 1;
graph[v][vertex] = 1;
path[--pathCount] = -1;
}
}
}
public boolean isPresent(int v)
{
for (int i = 0; i < pathCount - 1; i++)
if (path[i] == v)
return true;
return false;
}
public void display()
{
System.out.print("\nPath : ");
for (int i = 0; i <= V; i++)
System.out.print(path[i % V] +" ");
System.out.println();
}
public static void main (String[] args)
{
Scanner scan = new Scanner(System.in);
System.out.println("HamiltonianCycle Algorithm Test\n");
Ham hc = new Ham();
System.out.println("Enter number of vertices\n");
int V = scan.nextInt();
System.out.println("\nEnter matrix\n");
int[][] graph = new int[V][V];
for (int i = 0; i < V; i++)
for (int j = 0; j < V; j++)
graph[i][j] = scan.nextInt();
hc.findHamiltonianCycle(graph);
}
}