Reverse Left Words

src/offer_58.cpp

@@ -0,0 +1,17 @@
+#include "offer_58.hpp"
+
+void Solution::reverseSubStr(string &s, int begin, int end) {
+  for (; begin < end; ++begin, --end) {
+    char tmp = s[begin];
+    s[begin] = s[end];
+    s[end] = tmp;
+  }
+}
+
+string Solution::reverseLeftWords(string s, int n) {
+  int len = s.length();
+  reverseSubStr(s, 0, n - 1);
+  reverseSubStr(s, n, len - 1);
+  reverseSubStr(s, 0, len - 1);
+  return s;
+}

src/s0151_reverse_words_in_a_string.cpp

@@ -1,14 +1,5 @@
 #include "s0151_reverse_words_in_a_string.hpp"
 
-// reverse a substring
-void reverseSubStr(string &s, int begin, int end) {
-  for (; begin < end; ++begin, --end) {
-    auto tmp = s[begin];
-    s[begin] = s[end];
-    s[end] = tmp;
-  }
-}
-
 string Solution::reverseWords(string s) {
   if (s.length() == 0) {
     return s;