D - Dance

https://atcoder.jp/contests/abc236/submissions/28754074

AtCoder/ABC236/D/D.cpp

@@ -0,0 +1,36 @@
+#include <iostream>
+
+using std::cin;
+using std::cout;
+using std::endl;
+
+int n, a[20][20], ans;
+bool vis[20];
+
+void dfs(int pos, int val) {
+    while (vis[pos]) pos++;
+    if (pos == n + 1) {
+        ans = std::max(ans, val);
+        return;
+    }
+    for (int i = pos + 1; i <= n; i++) {
+        if (vis[i]) continue;
+        vis[i] = true;
+        dfs(pos + 1, val ^ a[i][pos]);
+        vis[i] = false;
+    }
+}
+
+int main() {
+    cin >> n;
+    n <<= 1;
+    for (int i = 1; i <= n; i++) {
+        for (int j = i + 1; j <= n; j++) {
+            cin >> a[i][j];
+            a[j][i] = a[i][j];
+        }
+    }
+    dfs(1, 0);
+    cout << ans << endl;
+    return 0;
+}