209 accepted

Author: aQua

Algorithms/0209.minimum-size-subarray-sum/README.md

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+# [209. Minimum Size Subarray Sum](https://leetcode.com/problems/minimum-size-subarray-sum/)
+
+## 题目
+Given an array of n positive integers and a positive integer s, find the minimal length of a contiguous subarray of which the sum ≥ s. If there isn't one, return 0 instead.
+
+For example, given the array `[2,3,1,2,4,3]` and s = `7`,
+the subarray `[4,3]` has the minimal length under the problem constraint.
+
+**More practice:**
+
+If you have figured out the O(n) solution, try coding another solution of which the time complexity is O(n log n).
+
+## 解题思路
+
+见程序注释

Algorithms/0209.minimum-size-subarray-sum/minimum-size-subarray-sum.go

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+package Problem0209
+
+func minSubArrayLen(s int, a []int) int {
+	n := len(a)
+
+	if n == 0 {
+		return 0
+	}
+
+	res, i, j, sum := n+1, 0, 0, 0
+
+	for j < n {
+		sum += a[j]
+		j++
+
+		for sum >= s {
+			sum -= a[i]
+			i++
+			if res > j-i+1 {
+				res = j - i + 1
+			}
+		}
+	}
+
+	return res % (n + 1)
+}

Algorithms/0209.minimum-size-subarray-sum/minimum-size-subarray-sum_test.go

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+package Problem0209
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+type question struct {
+	para
+	ans
+}
+
+// para 是参数
+type para struct {
+	s    int
+	nums []int
+}
+
+// ans 是答案
+type ans struct {
+	one int
+}
+
+func Test_Problem0209(t *testing.T) {
+	ast := assert.New(t)
+
+	qs := []question{
+
+		question{
+			para{
+				15,
+				[]int{1, 2, 3, 4, 5},
+			},
+			ans{
+				5,
+			},
+		},
+
+		question{
+			para{
+				700,
+				[]int{2, 3, 1, 2, 4, 3},
+			},
+			ans{
+				0,
+			},
+		},
+
+		question{
+			para{
+				7,
+				[]int{2, 3, 1, 2, 4, 3},
+			},
+			ans{
+				2,
+			},
+		},
+
+		question{
+			para{
+				7,
+				[]int{},
+			},
+			ans{
+				0,
+			},
+		},
+		// 如需多个测试，可以复制上方元素。
+	}
+
+	for _, q := range qs {
+		a, p := q.ans, q.para
+		fmt.Printf("~~%v~~\n", p)
+
+		ast.Equal(a.one, minSubArrayLen(p.s, p.nums), "输入:%v", p)
+	}
+}