From 09e60215e4e174f6b2ce814c4a44797490b3743b Mon Sep 17 00:00:00 2001
From: Baoshuo <i@baoshuo.ren>
Date: Sat, 26 Mar 2022 19:28:20 +0800
Subject: [PATCH] =?UTF-8?q?4318.=20=E6=9C=80=E7=9F=AD=E8=B7=AF=E5=BE=84?=
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https://www.acwing.com/problem/content/submission/code_detail/12517850/
---
 AcWing/4318/4318.cpp | 47 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 AcWing/4318/4318.cpp

diff --git a/AcWing/4318/4318.cpp b/AcWing/4318/4318.cpp
new file mode 100644
index 00000000..97e64ce4
--- /dev/null
+++ b/AcWing/4318/4318.cpp
@@ -0,0 +1,47 @@
+#include <iostream>
+#include <map>
+#include <string>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int to[5][2] = {{0, 0}, {0, -1}, {0, 1}, {-1, 0}, {1, 0}};
+
+int x, y;
+std::string s;
+std::map<int, std::map<int, bool>> vis;
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin >> s;
+    vis[x][y] = true;
+    for (char c : s) {
+        int xx = 0, yy = 0;
+        if (c == 'U') {
+            y--;
+            yy--;
+        } else if (c == 'D') {
+            y++;
+            yy++;
+        } else if (c == 'L') {
+            x--;
+            xx--;
+        } else if (c == 'R') {
+            x++;
+            xx++;
+        }
+
+        if (vis[x][y]) {
+            cout << "NO" << endl;
+            exit(0);
+        }
+
+        vis[x][y] = true;
+        for (int i = 1; i <= 4; i++) {
+            vis[x + to[i][0] - xx][y + to[i][1] - yy] = true;
+        }
+    }
+    cout << "YES" << endl;
+    return 0;
+}