git reimport

archive/2016.07/2016.07.23 - unsorted/Timus1651.java

@@ -0,0 +1,105 @@
+package chelper;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+import java.util.Queue;
+
+import io.InputReader;
+import io.OutputWriter;
+
+public class Timus1651 {
+  public void solve2(int testNumber, InputReader in, OutputWriter out) {
+    int n = in.nextInt();
+    int[] a = in.nextIntArray(n);
+
+    int[] best = new int[100000];
+    int[] from = new int[100000];
+
+    Arrays.fill(best, Integer.MAX_VALUE);
+    best[a[0]] = 0;
+    from[a[0]] = 0;
+
+    for (int i = 1; i < n; i++) {
+      int t = a[i];
+      int p = a[i - 1];
+      if (best[t] > best[p] + 1) {
+        best[t] = best[p] + 1;
+        from[t] = i;
+      }
+    }
+
+    LinkedList<Integer> result = new LinkedList<>();
+
+    for (int c = n - 1; c >= 0;) {
+      int t = a[c];
+      result.addFirst(t);
+      c = from[t] - 1;
+    }
+
+    for (int i : result) {
+      out.print(i + " ");
+    }
+  }
+
+  public void solve(int testNumber, InputReader in, OutputWriter out) {
+    int n = in.nextInt();
+    int[] a = in.nextIntArray(n);
+
+    int M = 100100;
+
+    List<List<Integer>> edges = new ArrayList<>();
+
+    for (int i = 0; i < M; i++) {
+      edges.add(new ArrayList<>());
+    }
+
+    for (int i = 1; i < n; i++) {
+      int t = a[i];
+      int p = a[i - 1];
+      edges.get(p).add(t);
+    }
+
+    int start = a[0];
+    int finish = a[n - 1];
+
+    int[] dist = new int[M];
+    Arrays.fill(dist, Integer.MAX_VALUE);
+    dist[start] = 0;
+
+    int[] from = new int[M];
+    from[start] = -1;
+
+    List<Integer> vertices = new ArrayList<>();
+    vertices.add(a[0]);
+    while (!vertices.isEmpty()) {
+      List<Integer> newVertices = new ArrayList<>();
+
+      for (int i : vertices) {
+        for (int j : edges.get(i)) {
+          if (dist[j] == Integer.MAX_VALUE) {
+            dist[j] = dist[i] + 1;
+            from[j] = i;
+            newVertices.add(j);
+          }
+        }
+      }
+
+      vertices = newVertices;
+    }
+
+    LinkedList<Integer> result = new LinkedList<>();
+
+    for (int t = finish; t >= 0;) {
+      result.addFirst(t);
+      t = from[t];
+    }
+
+    for (int i : result) {
+      out.print(i + " ");
+    }
+  }
+}