Create replace-the-substring-for-balanced-string.cpp

Author: kamyu104

C++/replace-the-substring-for-balanced-string.cpp

@@ -0,0 +1,26 @@
+// Time:  O(n)
+// Space: O(1)
+
+class Solution {
+public:
+    int balancedString(string s) {
+        unordered_map<int, int> count;
+        for (const auto& c : s) {
+            ++count[c];
+        }
+        int result = s.length();
+        int left = 0;
+        for (int right = 0; right < s.length(); ++right) {
+            --count[s[right]];
+            while (left < s.length() &&
+                   all_of(count.cbegin(), count.cend(),
+                          [&s](const auto& kvp) {
+                              return kvp.second <= s.length() / 4;
+                          })) {
+                result = min(result, right - left + 1);
+                ++count[s[left++]];
+            }
+        }
+        return result;
+    }
+};