528. Random Pick with Weight

Author: Partho Biswas

README.md

@@ -344,6 +344,7 @@ Check this [golden](https://tinyurl.com/ujopecz) post.
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+|29| **[528. Random Pick with Weight](https://tinyurl.com/vf8bruk)**| [Python](https://tinyurl.com/wu6rdaw/528_Random_Pick_with_Weight.py)| **[Vid 1](https://tinyurl.com/usd5r25)**, **[Art 1](https://tinyurl.com/rgwt57q)** | Medium | Very tricky |
 
 </p>
 </details>

leetcode.com/python/528_Random_Pick_with_Weight.py

@@ -0,0 +1,23 @@
+import bisect
+import random
+class Solution(object):
+
+    def __init__(self, w):
+        """
+        :type w: List[int]
+        """
+        self.prefisSum = w
+        for i in range(1, len(self.prefisSum)):
+            self.prefisSum[i] = self.prefisSum[i] + self.prefisSum[i - 1]
+
+
+    def pickIndex(self):
+        """
+        :rtype: int
+        """
+        target = random.randint(1, self.prefisSum[-1])
+        return bisect.bisect_left(self.prefisSum, target)
+
+# Your Solution object will be instantiated and called as such:
+# obj = Solution(w)
+# param_1 = obj.pickIndex()