0076-minimum-window-substring.java

classSolution {

//sliding window
publicStringminWindow(Strings, Stringt) {
HashMap<Character, Integer> map = newHashMap<>();

for (charx : t.toCharArray()) {
map.put(x, map.getOrDefault(x, 0) + 1);
 }

intmatched = 0;
intstart = 0;
intminLen = s.length() + 1;
intsubStr = 0;
for (intendWindow = 0; endWindow < s.length(); endWindow++) {
charright = s.charAt(endWindow);
if (map.containsKey(right)) {
map.put(right, map.get(right) - 1);
if (map.get(right) == 0) matched++;
 }

while (matched == map.size()) {
if (minLen > endWindow - start + 1) {
minLen = endWindow - start + 1;
subStr = start;
 }
chardeleted = s.charAt(start++);
if (map.containsKey(deleted)) {
if (map.get(deleted) == 0) matched--;
map.put(deleted, map.get(deleted) + 1);
 }
 }
 }
returnminLen > s.length() ? "" : s.substring(subStr, subStr + minLen);
 }
}