Create 14-coprobber.cpp

Author: LeTrongDat

Baltic/14-coprobber.cpp

@@ -0,0 +1,51 @@
+/*
+    Author: Le Trong Dat
+    Idea:
+        * W(C, R, T) = True/False. True if Cop wins and False if Cop loses.
+        * W(i, i, 0/1) = true because Cop already won.
+        * W(C, R, 0) = True <=> Exists one state W(X, R, 1) = true.
+        * W(C, R, 1) = true <=> All states W(C, X, 0) = true.
+*/
+#include "coprobber.h"
+#include <bits/stdc++.h>
+const int maxN = 500;
+using namespace std;
+#define forn(i, a, b)   for(int i=a; i<=b; ++i)
+#define repn(i, a, b)   for(int i=a; i <b; ++i)
+
+int cur;
+int mov[maxN][maxN], deg[maxN][maxN];
+int W[maxN][maxN][2];
+int start(int N, bool A[maxN][maxN]) {
+    queue < tuple < int, int, int > > q;
+    repn(i, 0, N) repn(j, 0, N) repn(k, 0, N) deg[i][j] += A[j][k];
+    repn(i, 0, N) forn(turn, 0, 1) {
+        W[i][i][turn] = 1;
+        q.push({i, i, turn});
+    }
+    while (q.size()) {
+        int c, r, t;
+        tie(c, r, t) = q.front();
+        q.pop();
+        repn(i, 0, N) { 
+            if (t) {
+                if ( (A[c][i] || i == c) && !W[i][r][0]) {
+                    mov[i][r] = c;
+                    W[i][r][0] = true;
+                    q.push({i, r, 0});
+                }
+                continue;
+            }
+            if (A[r][i] && !W[c][i][1] && --deg[c][i] < 1) {
+                W[c][i][1] = true;
+                q.push({c, i, 1});
+            }
+        }
+    }
+    bool ok = true;
+    repn(i, 0, N) ok &= W[0][i][0];
+    return (ok ? 0 : -1);
+}
+int nextMove(int R) {
+    return cur = mov[cur][R];
+}