smallestTriplet.js

amit265 · amit265 · commit 5a5820d51a0c · 2026-02-21T11:53:48.000+05:30
diff --git a/javascript/4_array-programs/smallestTriplet.js b/javascript/4_array-programs/smallestTriplet.js
@@ -0,0 +1,114 @@
+// 35. Find Smallest Difference Triplet from Three Arrays
+
+// Approach 1: Brute Force
+
+{
+  function findSmallestDifferenceTriplet(arr1, arr2, arr3) {
+    let minDifference = Number.MAX_SAFE_INTEGER;
+    let resultTriplet;
+    for (let i = 0; i < arr1.length; i++) {
+      for (let j = 0; j < arr2.length; j++) {
+        for (let k = 0; k < arr3.length; k++) {
+          const maxNum = Math.max(arr1[i], arr2[j], arr3[k]);
+          const minNum = Math.min(arr1[i], arr2[j], arr3[k]);
+          const difference = maxNum - minNum;
+          if (difference < minDifference) {
+            minDifference = difference;
+            resultTriplet = [arr1[i], arr2[j], arr3[k]];
+          }
+        }
+      }
+    }
+    return resultTriplet;
+  }
+
+  const arr1 = [1, 2, 3, 4, 7];
+  const arr2 = [5, 10, 12];
+  const arr3 = [8, 9, 11, 14];
+  console.log(findSmallestDifferenceTriplet(arr1, arr2, arr3));
+}
+
+// Approach 2: Merge and Track
+
+{
+  function findSmallestDifferenceTriplet(arr1, arr2, arr3) {
+    let i = 0;
+    let j = 0;
+    let k = 0;
+    let minDifference = Number.MAX_SAFE_INTEGER;
+    let resultTriplet;
+    while (i < arr1.length && j < arr2.length && k < arr3.length) {
+      const maxNum = Math.max(arr1[i], arr2[j], arr3[k]);
+      const minNum = Math.min(arr1[i], arr2[j], arr3[k]);
+      const difference = maxNum - minNum;
+      if (difference < minDifference) {
+        minDifference = difference;
+        resultTriplet = [arr1[i], arr2[j], arr3[k]];
+      }
+      if (arr1[i] === minNum) {
+        i++;
+      } else if (arr2[j] === minNum) {
+        j++;
+      } else {
+        k++;
+      }
+    }
+
+    return resultTriplet;
+  }
+
+  const arr1 = [1, 2, 3, 4, 7];
+  const arr2 = [50, 100, 142];
+  const arr3 = [8, 9, 11, 14];
+  console.log(findSmallestDifferenceTriplet(arr1, arr2, arr3));
+}
+
+// Method 3: Binary Search for Efficient Element Matching
+{
+  function binarySearch(arr, target) {
+    let left = 0;
+    right = arr.length - 1;
+    while (left <= right) {
+      let mid = Math.floor((left + right) / 2);
+      if (arr[mid] === target) return mid;
+      if (arr[mid] < target) left = mid + 1;
+      else right = mid - 1;
+    }
+    return right;
+  }
+
+  function findSmallestDifferenceTriplet(arr1, arr2, arr2) {
+    let minDifference = Number.MAX_SAFE_INTEGER;
+    let resultTriplet = [];
+
+    for (let i = 0; i < arr1.length; i++) {
+      let a = arr1[i];
+      // find closest element in arr2
+      let pos2 = binarySearch(arr2, a);
+      let b1 = arr2[pos2] || Number.MAX_SAFE_INTEGER;
+      let b2 = arr2[pos2 + 1] || Number.MAX_SAFE_INTEGER;
+      let pos3 = binarySearch(arr3, a);
+      let c1 = arr3[pos3] || Number.MAX_SAFE_INTEGER;
+      let c2 = arr3[pos3 + 1] || Number.MAX_SAFE_INTEGER;
+
+      for (let b of [b1, b2]) {
+        for (let c of [c1, c2]) {
+          let triplet = [a, b, c];
+          let maxNum = Math.max(a, b, c);
+          let minNum = Math.min(a, b, c);
+          let difference = maxNum - minNum;
+          if (difference < minDifference) {
+            minDifference = difference;
+            resultTriplet = triplet;
+          }
+        }
+      }
+    }
+    return resultTriplet;
+  }
+
+  const arr1 = [1, 2, 3, 4, 7];
+  const arr2 = [5, 10, 12];
+  const arr3 = [8, 9, 11, 14];
+  console.log(findSmallestDifferenceTriplet(arr1, arr2, arr3));
+}
