更新

2025-12-23 08:04:26 +08:00
parent 56ae0d7124
commit 1398ae9e17
111 changed files with 5910 additions and 0 deletions
@@ -0,0 +1,30 @@
+#include <stdio.h>
+#include <stdlib.h>
+#ifdef _WIN32
+#include <windows.h>
+#endif
+
+typedef unsigned long long ull;
+
+int main(void)
+{
+#ifdef _WIN32
+    system("chcp 65001 > nul");
+    SetConsoleOutputCP(65001);
+    SetConsoleCP(65001);
+#endif
+    unsigned long long n;
+    if (scanf("%llu", &n) != 1)
+        return 0;
+    unsigned long long ans = 0ULL;
+    for (unsigned long long factor = 1ULL; factor <= n; factor *= 10ULL)
+    {
+        unsigned long long high = n / (factor * 10ULL);
+        unsigned long long low = n % factor;
+        unsigned long long cur = (n / factor) % 10ULL;
+        unsigned long long term = factor * (high * 45ULL + (cur * (cur - 1ULL)) / 2ULL) + cur * (low + 1ULL);
+        ans += term;
+    }
+    printf("%llu\n", ans);
+    return 0;
+}