Merge pull request #5 from imageslr/patch-1

78 题新增位运算的解法

Algorithms/0078. Subsets/78. Subsets.go

@@ -41,3 +41,24 @@ func subsets1(nums []int) [][]int {
 	}
 	return res
 }
+
+// 解法三：位运算的方法
+func subsets2(nums []int) [][]int {
+	if len(nums) == 0 {
+		return nil
+	}
+	res := [][]int{}
+	sum := 1 << uint(len(nums))
+	for i := 0; i < sum; i++ {
+		stack := []int{}
+		tmp := i // i 从 000...000 到 111...111
+		for j := len(nums) - 1; j >= 0; j-- { // 遍历 i 的每一位
+			if tmp & 1 == 1 {
+				stack = append([]int{nums[j]}, stack...)
+			}
+			tmp >>= 1
+		}
+		res = append(res, stack)
+	}
+	return res
+}