Commit 398cdea

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solves #797: All Paths From Source to Target in java

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`414`	`414`	`\| 783 \| [Minimum Distance Between BST Nodes](https://leetcode.com/problems/minimum-distance-between-bst-nodes) \| [![Java](assets/java.png)](src/MinimumAbsoluteDifferenceInBST.java) [![Python](assets/python.png)](python/minimum_distance_between_bst_nodes.py) \| \|`
`415`	`415`	`\| 788 \| [Rotated Digits](https://leetcode.com/problems/rotated-digits) \| \| \|`
`416`	`416`	`\| 796 \| [Rotate String](https://leetcode.com/problems/rotate-string) \| [![Java](assets/java.png)](src/RotateString.java) \| \|`
	`417`	`+\| 797 \| [All Paths From Source to Target](https://leetcode.com/problems/all-paths-from-source-to-target) \| [![Java](assets/java.png)](src/AllPathsFromSourceToTarget.java) \| \|`
`417`	`418`	`\| 800 \| [Similar RGB Color](https://leetcode.com/problems/similar-rgb-color) \| \| \|`
`418`	`419`	`\| 804 \| [Unique Morse Code Words](https://leetcode.com/problems/unique-morse-code-words) \| [![Java](assets/java.png)](src/UniqueMorseCodeWords.java) \| \|`
`419`	`420`	`\| 806 \| [Number of Lines to Write String](https://leetcode.com/problems/number-of-lines-to-write-string) \| [![Java](assets/java.png)](src/NumberOfLinesToWriteInString.java) \| \|`

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`@@ -0,0 +1,28 @@`
	`1`	`+// https://leetcode.com/problems/all-paths-from-source-to-target`
	`2`	`+// maximum edges for DAG = V-1, possible paths = 2^(V-1), for every path we clone path O(V)`
	`3`	`+// T: O(2^V * V)`
	`4`	`+// S: O(V)`
	`5`	`+`
	`6`	`+import java.util.ArrayList;`
	`7`	`+import java.util.List;`
	`8`	`+`
	`9`	`+public class AllPathsFromSourceToTarget {`
	`10`	`+ public List<List<Integer>> allPathsSourceTarget(int[][] graph) {`
	`11`	`+ final List<List<Integer>> result = new ArrayList<>();`
	`12`	`+ final int n = graph.length;`
	`13`	`+ dfs(graph, 0, n - 1, new ArrayList<>() {{ add(0); }}, result);`
	`14`	`+ return result;`
	`15`	`+ }`
	`16`	`+`
	`17`	`+ private static void dfs(int[][] graph, int current, int target, List<Integer> path, List<List<Integer>> result) {`
	`18`	`+ if (current == target) {`
	`19`	`+ result.add(new ArrayList<>(path));`
	`20`	`+ return;`
	`21`	`+ }`
	`22`	`+ for (int edge : graph[current]) {`
	`23`	`+ path.add(edge);`
	`24`	`+ dfs(graph, edge, target, path, result);`
	`25`	`+ path.removeLast();`
	`26`	`+ }`
	`27`	`+ }`
	`28`	`+}`

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Original file line number	Diff line number	Diff line change
`@@ -1,2 +1,51 @@`
	`1`	`+// T: O(N + E alp(N))`
	`2`	`+// S: O(N)`
	`3`	`+`
`1`	`4`	`public class HelloWorld {`
	`5`	`+ private static final class DisjointSet {`
	`6`	`+ private final int[] roots, rank;`
	`7`	`+`
	`8`	`+ public DisjointSet(int size) {`
	`9`	`+ roots = new int[size];`
	`10`	`+ rank = new int[size];`
	`11`	`+ for (int i = 0 ; i < size ; i++) {`
	`12`	`+ roots[i] = i;`
	`13`	`+ rank[i] = 1;`
	`14`	`+ }`
	`15`	`+ }`
	`16`	`+`
	`17`	`+ public int find(int num) {`
	`18`	`+ if (num == roots[num]) {`
	`19`	`+ return num;`
	`20`	`+ }`
	`21`	`+ return roots[num] = find(roots[num]);`
	`22`	`+ }`
	`23`	`+`
	`24`	`+ public boolean areConnected(int x, int y) {`
	`25`	`+ return find(x) == find(y);`
	`26`	`+ }`
	`27`	`+`
	`28`	`+ public void union(int x, int y) {`
	`29`	`+ final int rootX = find(x), rootY = find(y);`
	`30`	`+ if (rootX == rootY) {`
	`31`	`+ return;`
	`32`	`+ }`
	`33`	`+ if (rank[rootX] > rank[rootY]) {`
	`34`	`+ roots[rootY] = rootX;`
	`35`	`+ } else if (rank[rootX] < rank[rootY]) {`
	`36`	`+ roots[rootX] = rootY;`
	`37`	`+ } else {`
	`38`	`+ roots[rootY] = rootX;`
	`39`	`+ rank[rootX]++;`
	`40`	`+ }`
	`41`	`+ }`
	`42`	`+ }`
	`43`	`+`
	`44`	`+ public boolean validPath(int n, int[][] edges, int source, int destination) {`
	`45`	`+ final DisjointSet disjointSet = new DisjointSet(n);`
	`46`	`+ for (int[] edge : edges) {`
	`47`	`+ disjointSet.union(edge[0], edge[1]);`
	`48`	`+ }`
	`49`	`+ return disjointSet.areConnected(source, destination);`
	`50`	`+ }`
`2`	`51`	`}`

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