complete 1707.py

zeta_python/completed/1707.py

@@ -0,0 +1,42 @@
+import sys
+
+input = sys.stdin.readline
+
+
+def color_reversal(c: int) -> int:
+    if c == 1:
+        return 2
+    else:
+        return 1
+
+
+def solve(V: int, E) -> str:
+
+    D = list(range(1, V + 1))
+    colored = [0] * (V + 1)
+    while D:
+        now = D.pop()
+        if not colored[now]:
+            colored[now] = 1
+        for target in E[now]:
+            if colored[target]:
+                if color_reversal(colored[now]) == colored[target]:
+                    continue
+                else:
+                    return "NO"
+            else:
+                colored[target] = color_reversal(colored[now])
+                D.append(target)
+    return "YES"
+
+
+if __name__ == "__main__":
+    K = int(input())
+    for _ in range(K):
+        V, C = map(int, input().split())
+        E = [[] for _ in range(V + 1)]
+        for _ in range(C):
+            u, v = map(int, input().split())
+            E[u].append(v)
+            E[v].append(u)
+        print(solve(V, E))