문제로

내가 푼 것

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class Solution {
    public int[] twoSum(int[] nums, int target) {
        int[] result = new int[2];
        for(int i = 0; i < nums.length; i++){
            for(int j = 0; j < nums.length; j++){
                if(i == j) continue;
                if(i > j) continue;
                if(nums[i]+nums[j] == target) {
                    result[0] = i;
                    result[1] = j;
                }
            }
        }
        return result;
    }
}

답안1

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class Solution {
public:
    vector<int> twoSum(vector<int>& nums, int target) {
        int n = nums.size();
        for (int i = 0; i < n - 1; i++) {
            for (int j = i + 1; j < n; j++) {
                if (nums[i] + nums[j] == target) {
                    return {i, j};
                }
            }
        }
        return {}; // No solution found
    }
};

답안2

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class Solution {
    public int[] twoSum(int[] nums, int target) {
        Map<Integer, Integer> numMap = new HashMap<>();
        int n = nums.length;

        // Build the hash table
        for (int i = 0; i < n; i++) {
            numMap.put(nums[i], i);
        }

        // Find the complement
        for (int i = 0; i < n; i++) {
            int complement = target - nums[i];
            if (numMap.containsKey(complement) && numMap.get(complement) != i) {
                return new int[]{i, numMap.get(complement)};
            }
        }

        return new int[]{}; // No solution found
    }
}

답안3

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class Solution {
    public int[] twoSum(int[] nums, int target) {
        Map<Integer, Integer> numMap = new HashMap<>();
        int n = nums.length;

        for (int i = 0; i < n; i++) {
            int complement = target - nums[i];
            if (numMap.containsKey(complement)) {
                return new int[]{numMap.get(complement), i};
            }
            numMap.put(nums[i], i);
        }

        return new int[]{}; // No solution found
    }
}