[Leetcode] 1. twosum

문제 링크 : https://leetcode.com/problems/two-sum/

Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target.

You may assume that each input would have exactly one solution, and you may not use the same element twice.

You can return the answer in any order.

Example 1:

Input: nums = [2,7,11,15], target = 9
Output: [0,1]
Output: Because nums[0] + nums[1] == 9, we return [0, 1].

Example 2:

Input: nums = [3,2,4], target = 6
Output: [1,2]

Example 3:

Input: nums = [3,3], target = 6
Output: [0,1]

Constraints:

• 2 <= nums.length <= 104
• 109 <= nums[i] <= 109
• 109 <= target <= 109
• Only one valid answer exists.

풀이

nums = [1,2,3,4,5]

for i in range(len(nums)):
    for j in range(i + 1, len(nums)):
        print(i, j)
print(len(nums))
print(range(len(nums)))

        
print("*************************************")
print("*************************************")
        
for i in range(len(nums) - 1):
    for j in range(i + 1, len(nums)):
        print(i, j)
print(len(nums) -1)
print(range(len(nums) -1))

for i in range(len(nums)):
    for j in range(i + 1, len(nums)):
        print(i, j)
        
print("*************************************")
print("*************************************")

for i in range(len(nums)):
    for j in range(len(nums)): # 각각 1번씩만 매칭이 되면 되니까, + 1를 하는게 좋겠다.
        print(i, j)

print("*************************************")
print("*************************************")

class Solution:
    def twoSum(self, nums, target):
        for i in range(len(nums)):
            for j in range(i+1, len(nums)):
                if target == nums[i] + nums[j]:
                    return [i, j]

solu = Solution()
print(solu.twoSum([1,2,3,1,5], 4))

# 출력
0 1
0 2
0 3
0 4
1 2
1 3
1 4
2 3
2 4
3 4
5
range(0, 5)
*************************************
*************************************
0 1
0 2
0 3
0 4
1 2
1 3
1 4
2 3
2 4
3 4
4
range(0, 4)
0 1
0 2
0 3
0 4
1 2
1 3
1 4
2 3
2 4
3 4
*************************************
*************************************
0 0
0 1
0 2
0 3
0 4
1 0
1 1
1 2
1 3
1 4
2 0
2 1
2 2
2 3
2 4
3 0
3 1
3 2
3 3
3 4
4 0
4 1
4 2
4 3
4 4
*************************************
*************************************
[0, 2]