[LeetCode]数组——存在重复

class Solution {
public:
    bool containsDuplicate(vector<int>& nums) {
        unordered_map<int, int>m;
        for (int i = 0; i < nums.size(); i++) {
            if (m.find(nums[i]) != m.end())
                return true;
            ++m[nums[i]];
        }
        return false;
    }
};

bool containsDuplicate(int* nums, int numsSize) {
    int i, j;
    for (i = 0; i<numsSize; i++)
    {
        for (j = i + 1; j<numsSize; j++)
        {
            if (nums[i] == nums[j])
                return true;
        }
    }
    return false;
}