Create count-prefixes-of-a-given-string.cpp

C++/count-prefixes-of-a-given-string.cpp

@@ -0,0 +1,16 @@
+// Time:  O(n * l)
+// Space: O(1)
+
+// string
+class Solution {
+public:
+    int countPrefixes(vector<string>& words, string s) {
+        const auto& startsWith = [](const auto& s, const auto& prefix) {
+            return (size(prefix) <= size(s) && s.compare(0, size(prefix), prefix, 0, size(prefix)) == 0);
+        };
+        return accumulate(cbegin(words), cend(words), 0,
+                          [&](const auto& total, const auto& x) {
+                              return total + startsWith(s, x);
+                          });
+    }
+};