LeetCode题解-Go 0x0001 two-sum

给定一个整数数组nums和一个目标值 target，请你在该数组中找出和为目标值的那两个整数，并返回他们的数组下标。 你可以假设每种输入只会对应一个答案。但是，你不能重复利用这个数组中同样的元素。

Given an array of integers, return indices of the two numbers such that they add up to a specific target. You may assume that each input would have exactly one solution, and you may not use the same element twice.

来源：力扣（LeetCode） 链接： leetcode-cn.com/problems/tw… 著作权归领扣网络所有。商业转载请联系官方授权，非商业转载请注明出处。

示例

给定 nums = [2, 7, 11, 15], target = 9

因为 nums[0] + nums[1] = 2 + 7 = 9
所以返回 [0, 1]
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• 思路一

代码实现

package problem0001

func twoSum(nums []int, target int) []int {
	index := make(map[int]int, len(nums))
	for i, b := range nums {
		if j, ok := index[target-b]; ok {
			return []int{j, i}
		}
		index[b] = i
	}
	return nil
}
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单元测试

package problem0001

import (
	"testing"

	"github.com/stretchr/testify/assert"
)

type para struct {
	one []int
	two int
}

type ans struct {
	one []int
}

type question struct {
	p para
	a ans
}

func TestTwoSum(t *testing.T) {
	ast := assert.New(t)
	qs := []question{
		question{
			p: para{
				one: []int{3, 2, 4},
				two: 6,
			},
			a: ans{
				one: []int{1, 2},
			},
		},
		question{
			p: para{
				one: []int{3, 2, 4},
				two: 8,
			},
			a: ans{
				one: nil,
			},
		},
	}
	for _, q := range qs {
		a, p := q.a, q.p
		ast.Equal(a.one, twoSum(p.one, p.two), "输入:%v", p)
	}
}

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