两数之和

function twoSum(nums: number[], target: number): number[] {
  for (let i = 0; i < nums.length; i++) {
    for (let j = i + 1; j < nums.length; j++) {
      if (nums[i] + nums[j] === target) {
        return [i, j]
      }
    }
  }
}

function twoSum(nums: number[], target: number): number[] {
  const map = new Map()

  for (let i = 0; i < nums.length; i++) {
    const value = nums[i]
    if (map.has(target - value)) {
      return [map.get(target - value), i]
    } else {
      map.set(value, i)
    }
  }
}