1 files changed, 37 insertions, 0 deletions

diff --git a/04_graph_algorithms/building_teams_1668.cpp b/04_graph_algorithms/building_teams_1668.cpp
new file mode 100644
index 0000000..c98e14d
--- /dev/null
+++ b/04_graph_algorithms/building_teams_1668.cpp
@@ -0,0 +1,37 @@
+#include <iostream>
+#include <vector>
+
+bool visit(size_t i, int c, const std::vector<std::vector<size_t>>& a,
+    std::vector<int>& t) {
+        if (t[i] != 0) return true;
+        t[i] = c;
+        for (auto j : a[i])
+                if (t[j] == c)
+                        return false;
+                else if (!visit(j, 3-c, a, t)) return false;
+        return true;
+}
+
+int main() {
+        size_t n, m;
+        std::cin >> n >> m;
+        std::vector<std::vector<size_t>> a(n);
+        for (size_t i = 0; i < m; i++) {
+                size_t x, y;
+                std::cin >> x >> y;
+                a[x-1].push_back(y-1);
+                a[y-1].push_back(x-1);
+        }
+
+        std::vector<int> t(n);
+        for (size_t i = 0; i < n; i++) {
+                if (t[i] == 0) {
+                        if (!visit(i, 1, a, t)) {
+                                std::cout << "IMPOSSIBLE\n";
+                                return 0;
+                        }
+                }
+        }
+        for (auto x : t) std::cout << x << " ";
+        std::cout << "\n";
+}