'commit'

TangDou/LuoGuBook/L4_8.cpp

@@ -0,0 +1,19 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int main() {
+    int n, x, cnt = 0;
+    cin >> n >> x;
+    for (int i = 1; i <= n; i++) {
+        int t = i;
+        //注意这里的数位分离技巧
+        while (t > 0) {
+            int ys = t % 10;
+            if (ys == x) cnt++;
+            t /= 10;
+        }
+    }
+    printf("%d", cnt);
+    return 0;
+}