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Commit e092d09

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1 parent 2524e74 commit e092d09

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4 files changed

+240
-1
lines changed

4 files changed

+240
-1
lines changed
Lines changed: 87 additions & 0 deletions
Original file line numberDiff line numberDiff line change
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import java.io.*;
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import java.util.*;
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class BipatriteDFSColouring {
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static BufferedReader br;
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static StringTokenizer st;
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static int nextInt() throws IOException {
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return Integer.parseInt(next());
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}
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static String next() throws IOException {
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while (st == null || !st.hasMoreTokens()) {
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st = new StringTokenizer(br.readLine());
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}
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return st.nextToken();
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}
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static long nextLong() throws IOException {
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return Long.parseLong(next());
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}
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public static void main(String args[]) throws IOException {
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br = new BufferedReader(new InputStreamReader(System.in));
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int t = nextInt();
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while (t-- > 0) {
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input();
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}
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br.close();
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}
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public static void input() throws IOException {
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int vertices = nextInt();
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int edges = nextInt();
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List<List<Integer>> adj = new ArrayList<>();
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for (int i = 0; i < vertices + 1; i++) {
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adj.add(new ArrayList<>());
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}
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for (int i = 0; i < edges; i++) {
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int source = nextInt();
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int destination = nextInt();
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adj.get(source).add(destination);
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adj.get(destination).add(source);
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}
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System.out.println(adj);
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int col[] = new int[vertices + 1];
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Arrays.fill(col, -1);
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System.out.println(dfs(adj, col));
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}
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static boolean dfs(List<List<Integer>> adj, int[] col) {
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for (int i = 1; i < col.length; i++) {
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if (col[i] == -1) {
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if (!dfs(i, adj, col)) {
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return false;
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}
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}
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}
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return true;
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}
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static boolean dfs(int node, List<List<Integer>> adj, int[] col) {
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if (col[node] == -1) {
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col[node] = 1;
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}
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for (int it : adj.get(node)) {
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if (col[it] == -1) {
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col[it] = 1 - col[node];
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if (!dfs(it, adj, col))
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return false;
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} else if (col[node] == col[it]) {
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return false;
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}
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}
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return true;
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}
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}
Lines changed: 104 additions & 0 deletions
Original file line numberDiff line numberDiff line change
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/**
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1
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9 10
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1 2
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2 3
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3 4
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4 5
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3 6
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6 5
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7 2
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7 8
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8 9
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9 5
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1 --> 2 --> 3 --> 4 --> 5 <--
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^ | ^ |
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| ^ | |
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7 6 ----------- |
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| |
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^ |
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8 --> 9 ---------------
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*/
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import java.io.*;
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import java.util.*;
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class DetectCycleInDirectedGraphDFS {
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static BufferedReader br;
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static StringTokenizer st;
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static int nextInt() throws IOException {
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return Integer.parseInt(next());
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}
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static String next() throws IOException {
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while (st == null || !st.hasMoreTokens()) {
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st = new StringTokenizer(br.readLine());
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}
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return st.nextToken();
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}
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static long nextLong() throws IOException {
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return Long.parseLong(next());
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}
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public static void main(String args[]) throws IOException {
48+
br = new BufferedReader(new InputStreamReader(System.in));
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int t = nextInt();
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while (t-- > 0) {
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input();
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}
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br.close();
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}
55+
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public static void input() throws IOException {
57+
int vertices = nextInt();
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int edges = nextInt();
59+
List<List<Integer>> adj = new ArrayList<>();
60+
for (int i = 0; i < vertices + 1; i++) {
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adj.add(new ArrayList<>());
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}
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for (int i = 0; i < edges; i++) {
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int source = nextInt();
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int destination = nextInt();
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adj.get(source).add(destination);
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}
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int vis[] = new int[vertices + 1];
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int dfsvis[] = new int[vertices + 1];
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System.out.println(adj);
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System.out.println(dfs(adj, vis, dfsvis));
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}
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static boolean dfs(List<List<Integer>> adj, int[] vis, int[] dfsvis) {
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for (int i = 0; i < vis.length; i++) {
78+
if (vis[i] == 0) {
79+
if (dfs(i, adj, vis, dfsvis) == true)
80+
return true;
81+
}
82+
}
83+
return false;
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}
85+
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static boolean dfs(int ind, List<List<Integer>> adj, int[] vis, int[] dfsvis) {
87+
vis[ind] = 1;
88+
dfsvis[ind] = 1;
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for (int it : adj.get(ind)) {
90+
if (vis[it] == 0) {
91+
if (dfs(it, adj, vis, dfsvis) == true) {
92+
return true;
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}
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} else if (dfsvis[it] == 1) {
95+
return true;
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}
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}
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dfsvis[ind] = 0;
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return false;
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}
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}

‎DSAPractice/graph/DetectCycleInUndirectedGraph.java‎ renamed to ‎DSAPractice/graph/DetectCycleInUndirectedGraphbfs.java‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -11,7 +11,7 @@ class Node {
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}
1212

1313
// using bfs
14-
public class DetectCycleInUndirectedGraph {
14+
public class DetectCycleInUndirectedGraphbfs {
1515
static StringTokenizer st;
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static BufferedReader br;
1717

Lines changed: 48 additions & 0 deletions
Original file line numberDiff line numberDiff line change
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import java.io.*;
2+
import java.util.*;
3+
4+
class TopologicalSortDFS {
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static BufferedReader br;
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static StringTokenizer st;
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static int nextInt() throws IOException {
9+
return Integer.parseInt(next());
10+
}
11+
12+
static String next() throws IOException {
13+
while (st == null || !st.hasMoreTokens()) {
14+
st = new StringTokenizer(br.readLine());
15+
}
16+
return st.nextToken();
17+
}
18+
19+
static long nextLong() throws IOException {
20+
return Long.parseLong(next());
21+
}
22+
23+
public static void main(String args[]) throws IOException {
24+
br = new BufferedReader(new InputStreamReader(System.in));
25+
int t = nextInt();
26+
while (t-- > 0) {
27+
input();
28+
}
29+
br.close();
30+
}
31+
32+
public static void input() throws IOException {
33+
int vertices = nextInt();
34+
int edges = nextInt();
35+
List<List<Integer>> adj = new ArrayList<>();
36+
for (int i = 0; i < vertices + 1; i++) {
37+
adj.add(new ArrayList<>());
38+
39+
}
40+
41+
for (int i = 0; i < edges; i++) {
42+
int source = nextInt();
43+
int destination = nextInt();
44+
adj.get(source).add(destination);
45+
}
46+
int vis[] = new int[vertices + 1];
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}
48+
}

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