From cf82beddae1ed4e64655964344818fa592f3650c Mon Sep 17 00:00:00 2001
From: Ren Baoshuo <i@baoshuo.ren>
Date: Fri, 17 Sep 2021 19:20:45 +0800
Subject: [PATCH] =?UTF-8?q?873.=20=E6=AC=A7=E6=8B=89=E5=87=BD=E6=95=B0?=
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https://www.acwing.com/problem/content/submission/code_detail/7779824/
---
 AcWing/873/873.cpp | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)
 create mode 100644 AcWing/873/873.cpp

diff --git a/AcWing/873/873.cpp b/AcWing/873/873.cpp
new file mode 100644
index 00000000..63d4e9ea
--- /dev/null
+++ b/AcWing/873/873.cpp
@@ -0,0 +1,26 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int n, x;
+
+int phi(int x) {
+    int res = x;
+    for (int i = 2; i * i <= x; i++) {
+        if (x % i == 0) {
+            res = res / i * (i - 1);
+            while (x % i == 0) x /= i;
+        }
+    }
+    if (x > 1) res = res / x * (x - 1);
+    return res;
+}
+
+int main() {
+    cin >> n;
+    while (n--) {
+        cin >> x;
+        cout << phi(x) << endl;
+    }
+    return 0;
+}