Adding medium/hard puzzles & challenges...

puzzles/medium/skynet-revolution-episode-1.cpp

@@ -0,0 +1,87 @@
+// https://www.codingame.com/ide/puzzle/skynet-revolution-episode-1
+// Xavier Morel - 2016-03-12
+
+#include <iostream>
+#include <string>
+#include <vector>
+#include <algorithm>
+
+using namespace std;
+
+typedef struct {
+    bool is_gateway = false;
+    vector<int> links;
+} Node;
+
+Node    *nodes;
+
+void remove_link(int a, int b)
+{
+    for (auto it = nodes[a].links.begin(); it != nodes[a].links.end(); it++) {
+        if (*it == b) {
+            nodes[a].links.erase(it);
+            break;
+        }
+    }
+
+    for (auto it = nodes[b].links.begin(); it != nodes[b].links.end(); it++) {
+        if (*it == a) {
+            nodes[b].links.erase(it);
+            break;
+        }
+    }
+    cout << a << " " << b << endl;
+}
+
+/**
+ * Auto-generated code below aims at helping you parse
+ * the standard input according to the problem statement.
+ **/
+int main()
+{
+    int N, L, E;
+    cin >> N >> L >> E; cin.ignore();
+    nodes = new Node[N];
+
+    for (int i = 0; i < L; i++) {
+        int N1, N2;
+        cin >> N1 >> N2; cin.ignore();
+        nodes[N1].links.push_back(N2);
+        nodes[N2].links.push_back(N1);
+    }
+
+    for (int i = 0; i < E; i++) {
+        int EI;
+        cin >> EI; cin.ignore();
+        nodes[EI].is_gateway = true;
+    }
+
+    // game loop
+    while (1) {
+        int SI;
+        cin >> SI; cin.ignore();
+
+        int a = 0;
+        int b = 0;
+
+        for (int i : nodes[SI].links) {
+            cerr << "Check node " << i << endl;
+            if (nodes[i].is_gateway && nodes[i].links.size() > 0) {
+                a = SI;
+                b = i;
+                break;
+            }
+        }
+
+        if (a == 0 && b == 0) {
+            for (int i = 0; i < N; i++) {
+                if (nodes[i].is_gateway && nodes[i].links.size() > 0) {
+                    a = i;
+                    b = nodes[i].links.back();
+                    break;
+                }
+            }
+        }
+        remove_link(a, b);
+    }
+}