leetcode-题6--Longest Consecutive Sequence

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main()
{
    int a[5] = { 1,3,5,6,7 };
    int cnt = 1;
    int max = 1;
    sort(a, a + 5);
    for (int i = 1; i < 5; ++i)
    {
        if (a[i] == a[i - 1] + 1)
        {
            cnt++;
            max = max > cnt ? max : cnt;
        }
        else {
            cnt = 1;
            max = 1;
        }
    }
    cout << max << endl;
    system("pause");
    return 0;
}

解法2：

#include <iostream>
#include <algorithm>
#include <unordered_map>

using namespace std;

int main()
{
    int a[6] = { 100,2,3,200,4,5 };
    unordered_map<int, bool>nums;
    for (auto i : a)
        nums[i] = false;
    int len = 1;
    int m = 1;
    for (auto i : a)
    {
        if (nums[i])continue;
        for (int j = i + 1; nums.find(j) != nums.end(); ++j)
        {
            len++;
            nums[j] = true;
        }
        for (int j = i - 1; nums.find(j) != nums.end(); --j)
        {
            len++;
            nums[j] = true;
        }
        m = max(len, m);
        len = 1;
    }
    cout << m << endl;
    system("pause");
    return 0;
}