[codility]Equi-leader

// you can also use includes, for example:// #include <algorithm>int getLeaderIndex(const vector<int> &A){    //...record the count of current winner number, then    int winnerNumber;    int winnerNumberLeftCount = 0;    for(int i = 0; i < A.size(); ++i)    {        if(winnerNumberLeftCount == 0)        {            winnerNumber = A[i];            winnerNumberLeftCount++;         }        else        {            if(winnerNumber == A[i]) winnerNumberLeftCount++;            else winnerNumberLeftCount--;        }    }    //...enumetate the array and count the occurence of this winner number,     if(winnerNumberLeftCount <= 0) return -1;    int winnerNumberRealCnt = 0;    int index;    for(int i = 0; i < A.size(); ++i)    {        if(A[i] == winnerNumber)         {            winnerNumberRealCnt++;            index = i;        }    }    //...if the last winner number is not the dominator then return -1    if(winnerNumberRealCnt <= (int)A.size()/2) return -1;    else return index;}int solution(vector<int> &A) {    // write your code in C++98    //...because equi_leader is both side arrays' leader, so it must also be    //leader of the whole array, so find out it first    int leaderIndex = getLeaderIndex(A);    if(leaderIndex == -1) return 0;    //...record the total count of leader number    int leaderNumber = A[leaderIndex];    int leaderNumTotalCnt = 0;    for(int i = 0; i < A.size(); ++i)        if(A[i] == leaderNumber) leaderNumTotalCnt++;    //...enumerate the whole array and keep records of the leader number's count in left side    // of the array, in the meantime check if current enumerated index can be the divider of equi_leader    int result = 0;    int leaderNumLeftCnt = 0;    for(int i = 0; i < A.size(); ++i)    {        if(A[i] == leaderNumber) leaderNumLeftCnt++;        //check        if(leaderNumLeftCnt > (i+1)/2 && (leaderNumTotalCnt-leaderNumLeftCnt) > (A.size()-i-1)/2)            result++;    }    //...return result    return result;}