pb 16

Author: EISAWESOME

README.md

@@ -230,3 +230,16 @@ Given a column number, return its alphabetical column id. For example, given 1,
 
 ### Solution
 [JS](pb15/answer.js) (9:18)
+
+
+---
+
+## 16
+> This problem was asked by Triplebyte.
+
+You are given n numbers as well as n probabilities that sum up to 1. Write a function to generate one of the numbers with its corresponding probability.
+For example, given the numbers [1, 2, 3, 4] and probabilities [0.1, 0.5, 0.2, 0.2], your function should return 1 10% of the time, 2 50% of the time, and 3 and 4 20% of the time.
+You can generate random numbers between 0 and 1 uniformly.
+
+### Solution
+[JS](pb16/answer.js) (12.41)

pb16/Problem.md

@@ -0,0 +1,5 @@
+> This problem was asked by Triplebyte.
+
+You are given n numbers as well as n probabilities that sum up to 1. Write a function to generate one of the numbers with its corresponding probability.
+For example, given the numbers [1, 2, 3, 4] and probabilities [0.1, 0.5, 0.2, 0.2], your function should return 1 10% of the time, 2 50% of the time, and 3 and 4 20% of the time.
+You can generate random numbers between 0 and 1 uniformly.

pb16/answer.js

@@ -0,0 +1,52 @@
+// Time : 12:41
+
+const roll = (arrNum, arrProb) => {
+
+    let ret = "";
+
+    let rnd = Math.random();
+
+
+    if(arrNum.length === arrProb.length) {
+        let sumProb = arrProb.reduce((acc, cur) => acc += cur, 0);
+        let isProbValid = sumProb === 1;
+    
+        if (isProbValid) {            
+    
+            let fused = arrNum.map((n, idx) => {
+                return {
+                    val: n,
+                    prob: arrProb[idx]
+                }
+            }).sort((a, b) => {
+                return b.prob - a.prob;
+            });
+    
+            fused.reduce((acc, cur) => {
+    
+                acc += cur.prob;
+    
+                cur.prob = acc;
+    
+                return acc;
+            }, 0);  
+    
+            let match = fused.find(f => f.prob >= rnd);    
+            
+            ret = `Rolled ${rnd}, returning ${match.val}`;    
+    
+        } else {
+            ret = "Probabilities does not add up to 1 !";
+        }
+    } else {
+        ret = "Arrays are not the same length !";
+    }
+
+    return ret;
+};
+
+
+let num = [1, 2, 3, 4];
+let prob = [0.1, 0.5, 0.2, 0.2];
+
+console.log(roll(num, prob));