'commit'

TangDou/XiTi/1277.cpp

@@ -0,0 +1,42 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+#define  ll long long
+
+int main() {
+    //输入+输出重定向
+    freopen("../1277.txt", "r", stdin);
+
+    int n;
+    cin >> n;
+    long long a, b;
+    //1位数，0-9
+    //2位数，10-99
+    //3位数, 100-999
+    //n位数  pow(10,n-1)  ---> pow(10,n)-1
+
+    n == 1 ? a = 0 : a = (ll) (pow(10, n - 1));
+    b = (ll) (pow(10, n) - 1);
+
+    int count = 0;
+    for (ll i = a; i <= b; i++) {
+        //数位分离
+        ll temp = i;
+        int c = 0;
+        while (temp) {
+            ll ct = temp % 10;
+            if (ct == 3) c++;
+            temp /= 10;
+        }
+        if (c % 2 == 0) {
+            count++;
+            count %= 12345;
+        }
+    }
+    cout << count << endl;
+
+    //关闭文件
+    fclose(stdin);
+    return 0;
+}