76. Minimum Window Substring (java)

Author: bluesword12350

solution/0076.Minimum Window Substring/Solution.java

@@ -0,0 +1,28 @@
+class Solution {
+    public String minWindow(String s, String t) {
+        int[] count = new int['z' - 'A' + 1];
+        int uniq = 0;
+        for (int i = 0; i < t.length(); ++i) {
+            if (++count[t.charAt(i) - 'A'] == 1) uniq++;
+        }
+        int found = 0,i = 0,j = 0;
+        int minLen = Integer.MAX_VALUE;
+        int minJ = Integer.MAX_VALUE;
+        while (found < uniq) {
+            while (i < s.length()) {
+                if (found >= uniq) break;
+                if (--count[s.charAt(i) - 'A'] == 0) found++;
+                i++;
+            }
+            if (found < uniq) break;
+            while (j < i && count[s.charAt(j) - 'A'] < 0) count[s.charAt(j++) - 'A']++;
+            if (i - j < minLen) {
+                minLen = i - j;
+                minJ = j;
+            }
+            count[s.charAt(j++) - 'A']++;
+            found--;
+        }
+        return minLen < Integer.MAX_VALUE ? s.substring(minJ, minJ + minLen) : "";
+    }
+}