added 0-1 Knapsack

Author: minhyeong-joe

BitManipulation/SingleNumber2/solution.py

@@ -1,12 +1,13 @@
 from typing import List
 
+
 class Solution:
     def singleNumber(self, nums: List[int]) -> int:
         binSum = 0
-        mask = bin((1<<32) -1)
+        mask = bin((1 << 32) - 1)
         uniqueBin = ""
         for num in nums:
-            binary = int(bin(num & int(mask,2))[2:])
+            binary = int(bin(num & int(mask, 2))[2:])
             print(num, "=", binary)
             binSum += binary
         print("sum =", binSum)
@@ -17,15 +18,15 @@ def singleNumber(self, nums: List[int]) -> int:
                 uniqueBin += "0"
         print("unique number in binary:", uniqueBin)
         if int(uniqueBin, 2) > 2**31:
-            uniqueBin = str(bin(int(uniqueBin,2)-1))
+            uniqueBin = str(bin(int(uniqueBin, 2)-1))
             print(uniqueBin)
-            print(bin((~int(uniqueBin, 2) & int(mask,2))))
-            return -(~int(uniqueBin, 2) & int(mask,2))
+            print(bin((~int(uniqueBin, 2) & int(mask, 2))))
+            return -(~int(uniqueBin, 2) & int(mask, 2))
         return int(uniqueBin, 2)
-        
+
 
 # test driver
 sol = Solution()
-input = [-19,-46,-19,-46,-9,-9,-19,17,17,17,-13,-13,-9,-13,-46,-28]
+input = [2, 3, 2, 2]
 print("Input:", input)
-print("Output:", sol.singleNumber(input))
+print("Output:", sol.singleNumber(input))

DynamicProgramming/ZeroOneKnapsack/README.md

@@ -0,0 +1,17 @@
+# 0-1 Knapsack
+
+## Problem:
+
+Given `weights`: list of weights where `weights[i]` represents the weight of `i-th` item,
+`values` : list of values where `values[i]` represents the value of `i-th` item,
+and `W`, total weight available,
+Find the maximum values that can be achieved within the limit of total weight.
+
+## Example:
+
+```
+Input: weights = [4, 5, 2, 3]
+       values =  [5, 3, 2, 4]
+       W = 7
+Output: 9
+```

DynamicProgramming/ZeroOneKnapsack/solution.py

@@ -0,0 +1,18 @@
+def knapsack(weights, values, W):
+    dp = [[0 for _ in range(W+1)] for _ in range(len(weights)+1)]
+    # print(dp)
+    for i in range(1, len(dp)):
+        for j in range(1, len(dp[i])):
+            if weights[i-1] <= j:
+                dp[i][j] = max(dp[i-1][j], dp[i-1]
+                               [j-weights[i-1]] + values[i-1])
+            else:
+                dp[i][j] = dp[i-1][j]
+    # print(dp)
+    return dp[-1][-1]
+
+
+weights = [4, 5, 2, 3]
+values = [5, 3, 2, 4]
+W = 7
+print(knapsack(weights, values, W))