add python 16 17 18 19 20 solutions

qinyii · qinyii · commit 58c7b5f422da · 2023-02-12T18:08:05.000+01:00
diff --git a/Problems/16-Minimum-Sum-of-Four-Digit-Number-After-Splitting-Digits/Minimun_Sum_of_Four_Digit_Number.py b/Problems/16-Minimum-Sum-of-Four-Digit-Number-After-Splitting-Digits/Minimun_Sum_of_Four_Digit_Number.py
@@ -0,0 +1,12 @@
+class Solution(object):
+    def minimumSum(self, num):
+        """
+        :type num: int
+        :rtype: int
+        """
+        res = []
+        while num:
+            res.append(num%10)
+            num/=10
+        res.sort()
+        return res[0]*10+res[2]+ res[1]*10+res[3]
diff --git a/Problems/17-Split-a-String-in-Balanced-Strings/Split_a_String_in_Balanced_Strings.py b/Problems/17-Split-a-String-in-Balanced-Strings/Split_a_String_in_Balanced_Strings.py
@@ -0,0 +1,15 @@
+class Solution(object):
+    def balancedStringSplit(self, s):
+        """
+        :type s: str
+        :rtype: int
+        """
+        res, tmp = 0,0
+        for char in s:
+            if char == 'R':
+                tmp += 1
+            else:
+                tmp -= 1
+            if tmp == 0:
+                res += 1
+        return res
diff --git a/Problems/18-Can-Place-Flowers/Can-Place-Flowers.py b/Problems/18-Can-Place-Flowers/Can-Place-Flowers.py
@@ -0,0 +1,13 @@
+class Solution(object):
+    def canPlaceFlowers(self, flowerbed, n):
+        """
+        :type flowerbed: List[int]
+        :type n: int
+        :rtype: bool
+        """
+        tmp = [0]+flowerbed+[0]
+        for i in range(1,len(tmp)-1):
+            if tmp[i-1] == 0 and tmp[i] == 0 and tmp[i+1] == 0:
+                tmp[i] = 1 
+                n -= 1   
+        return n <= 0
diff --git a/Problems/19-Partition-Labels/Partition_Labels.py b/Problems/19-Partition-Labels/Partition_Labels.py
@@ -0,0 +1,17 @@
+class Solution(object):
+    def partitionLabels(self, s):
+        """
+        :type s: str
+        :rtype: List[int]
+        """
+        last = [0] * 26
+        for i in range(len(s)):
+            last[ord(s[i]) - ord('a')] = i
+        res = []
+        left,right = 0,0
+        for i in range(len(s)):
+            right = max(right, last[ord(s[i]) - ord('a')])
+            if i == right:
+                res.append(right - left + 1)
+                left = i + 1
+        return res
diff --git a/Problems/20-Optimal-Partition-of-String/Optimal_Partition_of_String.py b/Problems/20-Optimal-Partition-of-String/Optimal_Partition_of_String.py
@@ -0,0 +1,15 @@
+class Solution(object):
+    def partitionString(self, s):
+        """
+        :type s: str
+        :rtype: int
+        """
+        res = 1
+        tmp = []
+        for char in s:
+            if char in tmp:
+                tmp = [char]
+                res +=1
+            else:
+                tmp.append(char)
+        return res
