761. 字符串中的数字个数

https://www.acwing.com/problem/content/submission/code_detail/2846021/

AcWing/761/761.cpp

@@ -0,0 +1,15 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int main() {
+    char c;
+    int ans = 0;
+    while (cin >> c) {
+        if ('0' <= c && c <= '9') {
+            ans++;
+        }
+    }
+    cout << ans << endl;
+    return 0;
+}