go implementation. binary search

410. Split Array Largest Sum/split_array_largest_sum.go

@@ -0,0 +1,47 @@
+package problem410
+
+func max(nums ...int) int {
+	max := nums[0]
+	for _, x := range nums {
+		if x > max {
+			max = x
+		}
+	}
+	return max
+}
+
+func sum(nums []int) int {
+	res := 0
+	for _, x := range nums {
+		res += x
+	}
+	return res
+}
+
+func split(nums []int, capacity int) int {
+	count := 1
+	pack := 0
+	for _, x := range nums {
+		pack += x
+		if pack > capacity {
+			pack = x
+			count++
+		}
+	}
+	return count
+}
+
+func splitArray(nums []int, m int) int {
+	left := max(nums...)
+	right := sum(nums)
+	var mid int
+	for left < right {
+		mid = (left + right) / 2
+		if split(nums, mid) > m {
+			left = mid + 1
+		} else {
+			right = mid
+		}
+	}
+	return left
+}