feat : minimum-window-substring

Author: ekgns33

minimum-window-substring/ekgns33.java

@@ -0,0 +1,30 @@
+class Solution {
+  public String minWindow(String s, String t) {
+    int[] freq = new int[128];
+    char[] str = s.toCharArray();
+    int minL = 0;
+    int minLength = Integer.MAX_VALUE;
+    int l = 0, r = 0, n = s.length();
+    for(char c : t.toCharArray()) {
+      freq[c-'A']++;
+    }
+    int resolved = t.length();
+    while(r < n) {
+      if(freq[str[r++] - 'A']-- > 0) {
+        resolved--;
+      }
+      while(resolved == 0) {
+        if(r - l < minLength) {
+          minL = l;
+          minLength = r - l;
+        }
+        if(freq[str[l] - 'A']++ == 0) {
+          resolved++;
+        }
+        l++;
+      }
+    }
+    if(minLength == Integer.MAX_VALUE) return "";
+    return new String(str, minL, minLength);
+  }
+}