3

Author: kedebug

MinimumWindowSubstring/MinimumWindowSubstring.cpp

@@ -0,0 +1,43 @@
+class Solution {
+public:
+    string minWindow(string S, string T) {
+        // Start typing your C/C++ solution below
+        // DO NOT write int main() function
+        
+        int needFind[256] = {0};
+        int hasFound[256] = {0};
+        int count = 0, minLen = INT_MAX;
+        string result = "";
+        
+        for (int i = 0; i < T.size(); i++)
+            needFind[T[i]] += 1;
+        
+        for (int low = 0, high = 0; high < S.size(); high++) {
+            if (needFind[S[high]] == 0) 
+                continue;
+            
+            hasFound[S[high]] += 1;
+            if (hasFound[S[high]] <= needFind[S[high]])
+                count += 1;
+            
+            if (count == T.size()) {
+                while (low < high) {
+                    if (needFind[S[low]] == 0) {
+                        low += 1;
+                        continue;
+                    }
+                    if (hasFound[S[low]] > needFind[S[low]])
+                        hasFound[S[low]] -= 1;
+                    else
+                        break;
+                    low += 1;
+                }
+                if (minLen > high - low + 1) {
+                    minLen = high - low + 1;
+                    result = S.substr(low, minLen);
+                }
+            }
+        }
+        return result;
+    }
+};