42 lines
814 B
Java
42 lines
814 B
Java
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import java.util.*;
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import java.util.stream.Stream;
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public class DfsNoRecursion {
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public static void dfs(List<Integer>[] graph, int root) {
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int n = graph.length;
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int[] curEdge = new int[n];
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int[] stack = new int[n];
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stack[0] = root;
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for (int top = 0; top >= 0; ) {
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int u = stack[top];
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if (curEdge[u] == 0) {
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System.out.println(u);
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}
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if (curEdge[u] < graph[u].size()) {
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int v = graph[u].get(curEdge[u]++);
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if (curEdge[v] == 0) {
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stack[++top] = v;
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}
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} else {
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--top;
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}
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}
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}
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// Usage example
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public static void main(String[] args) {
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List<Integer>[] g = Stream.generate(ArrayList::new).limit(3).toArray(List[]::new);
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g[0].add(1);
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g[1].add(0);
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g[0].add(2);
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dfs(g, 0);
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System.out.println();
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dfs(g, 1);
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System.out.println();
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dfs(g, 2);
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}
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}
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