solve the 76 leetcode task

76-task/main.py

@@ -0,0 +1,80 @@
+from collections import deque
+
+
+# my solution
+def minWindow(s, t):
+    dict_t = {}
+    for c in t:
+        dict_t[c] = dict_t.get(c, 0) + 1
+
+    dict_s = {}
+    l, r = 0, 0
+    buff = deque()
+    over = {}
+    best = [l, r]
+    for i in range(len(s)):
+        curr_char = s[i]
+        if curr_char in dict_t:
+            buff.append(i)
+            if dict_s.get(curr_char, 0) < dict_t[curr_char]:
+                dict_s[curr_char] = dict_s.get(curr_char, 0) + 1
+            elif dict_s.get(curr_char, 0) == dict_t[curr_char]:
+                over[curr_char] = over.get(curr_char, 0) + 1
+
+        if dict_s == dict_t:
+            while s[l] not in dict_t:
+                l += 1
+            while s[l] in over:
+                over[s[l]] -= 1
+                if over[s[l]] == 0:
+                    del over[s[l]]
+
+                buff.popleft()
+                l = buff[0]
+                r = i
+            if best[1] == 0 or best[1] - best[0] > r - l + 1:
+                best = [l, r + 1]
+        else:
+            r += 1
+
+    return s[best[0] : best[1]]
+
+
+def minWindow(s, t):
+    dict_t = {}
+    for c in t:
+        dict_t[c] = dict_t.get(c, 0) + 1
+
+    window_store = {}
+    best = [0, 0]
+    have, need = 0, len(dict_t)
+    l = 0
+    for r in range(len(s)):
+        curr_char = s[r]
+        if curr_char in dict_t:
+            window_store[curr_char] = window_store.get(curr_char, 0) + 1
+
+            if window_store[curr_char] == dict_t[curr_char]:
+                have += 1
+
+            while have == need:
+                # update result
+                if best[1] == 0 or best[1] - best[0] > r - l + 1:
+                    best = [l, r + 1]
+
+                if s[l] in dict_t:
+                    window_store[s[l]] -= 1
+                    if window_store[s[l]] < dict_t[s[l]]:
+                        have -= 1
+
+                l += 1
+
+    return s[best[0] : best[1]]
+
+
+if __name__ == "__main__":
+    assert minWindow("ADOBECODEBANC", "ABC") == "BANC"
+    assert minWindow("a", "a") == "a"
+    assert minWindow("a", "aa") == ""
+    assert minWindow("ab", "b") == "b"
+    assert minWindow("bbaac", "aba") == "baa"