Create 18.四数之和.js

Author: yinxin630

18.四数之和.js

@@ -0,0 +1,45 @@
+/**
+ * @param {number[]} nums
+ * @param {number} target
+ * @return {number[][]}
+ */
+var fourSum = function(nums, target) {
+    nums.sort((a, b) => a - b);
+
+    const result = [];
+    for (let i = 0; i < nums.length - 3; i++) {
+        if (i > 0 && nums[i] === nums[i - 1]) {
+            continue;
+        }
+
+        for (let j = i + 1; j < nums.length - 2; j++) {
+            if (j > i + 1 && nums[j] === nums[j - 1]) {
+                continue;
+            }
+
+            let a = j + 1;
+            let b = nums.length - 1;
+            while (a < b) {
+                const sum = nums[i] + nums[j] + nums[a] + nums[b];
+                if (sum === target) {
+                    result.push([nums[i], nums[j], nums[a], nums[b]]);
+                }
+                if (sum <= target) {
+                    do {
+                        a++;
+                    } while (nums[a] === nums[a - 1]);
+                }
+                if (sum >= target) {
+                    do {
+                        b--;
+                    } while (nums[b] === nums[b + 1]);
+                }
+            }
+        }
+    }
+
+    return result;
+};
+
+console.log(fourSum([-3,-1,0,2,4,5],
+    2));