leetcode-题5--优化

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

using namespace std;
//判断两个有序数组的第k个大的数

int dfs(int *a, int m, int *b, int n, int k)
{
    if (m > n)return dfs(b, n, a, m, k);
    if (m == 0)return b[k - 1];
    if (k == 1)return min(a[0], b[0]);

    int ai = min(k / 2, m), bi = k - ai;
    if (a[ai-1] < b[bi-1])
    {
        return dfs(a + ai, m - ai, b, n, k - ai);
    }
    if (a[ai-1] > b[bi-1])
    {
        return dfs(a, m, b + bi, n - bi, k - bi);
    }
    if (a[ai] == b[bi]) return a[ai];
}

int main()
{
    int a[5] = { 1,3,5,6,7 };
    int b[5] = { 2,3,4,6,7 };
    int res = dfs(a, 5, b, 5, 5);
    cout << res << endl;
    system("pause");
    return 0;
}