[hankerrank]Counter game

https://www.hackerrank.com/contests/w8/challenges/counter-game

关键是二分查找等于或最接近的小于target的数。可以使用和mid+1判断来比较~ 另有一种做法如下：

http://stackoverflow.com/questions/6553970/find-the-first-element-in-an-array-that-is-greater-than-the-target

#include <iostream>

#include <vector>

using namespace std;



uint64_t nextN(uint64_t N, vector<uint64_t> &vec) {

    int left = 0;

    int right = vec.size() - 1;

    while (left <= right) {

        int mid = (left + right) / 2;

        if (vec[mid] == N) {

            return N / 2;

        } else if (vec[mid] > N) {

           right = mid - 1; 

        } else {

           if (N < vec[mid + 1]) {

               return (N - vec[mid]);

           }

           left = mid + 1;

        }

    }

    return (N - vec[(left + right) / 2]);

}



int main() {

    int T;

    cin >> T;

    vector<uint64_t> vec;

    uint64_t p = 1;

    for (int i = 0; i < 64; i++) {

        vec.push_back(p);

        p *= 2;

    }

    while (T--) {

        uint64_t N;

        cin >> N;

        int move = 0;

        while (N != 1) {

            move++;

            N = nextN(N, vec);

        }

        if (move % 2 == 0) {

            cout << "Richard" << endl;

        } else {

            cout << "Louise" << endl;

        }

    }

    return 0;

}