feat: 2859. Sum of Values at Indices With K Set Bits

leetcode/2859/2859. Sum of Values at Indices With K Set Bits.go

@@ -0,0 +1,20 @@
+package _859
+
+func sumIndicesWithKSetBits(nums []int, k int) int {
+	sum := 0
+	for i, num := range nums {
+		if bitCount(i) == k {
+			sum += num
+		}
+	}
+	return sum
+}
+
+func bitCount(x int) int {
+	count := 0
+	for x > 0 {
+		count += x & 1
+		x >>= 1
+	}
+	return count
+}

leetcode/2859/2859. Sum of Values at Indices With K Set Bits_test.go

@@ -0,0 +1,31 @@
+package _859
+
+import "testing"
+
+func Test_sumIndicesWithKSetBits(t *testing.T) {
+	type args struct {
+		nums []int
+		k    int
+	}
+	tests := []struct {
+		name string
+		args args
+		want int
+	}{
+		{
+			name: "one",
+			args: args{
+				nums: []int{5, 10, 1, 5, 2},
+				k:    1,
+			},
+			want: 13,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := sumIndicesWithKSetBits(tt.args.nums, tt.args.k); got != tt.want {
+				t.Errorf("sumIndicesWithKSetBits() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}