A non-empty zero-indexed array A consisting of N integers is given.
The leader of this array is the value that occurs in more than half of the elements of A.
An equi leader is an index S such that 0 ≤ S < N − 1 and two sequences A[0], A[1], ..., A[S] and A[S + 1], A[S + 2], ..., A[N − 1] have leaders of the same value.
For example, given array A such that:
A[0] = 4 A[1] = 3 A[2] = 4 A[3] = 4 A[4] = 4 A[5] = 2
we can find two equi leaders:
- 0, because sequences: (4) and (3, 4, 4, 4, 2) have the same leader, whose value is 4.
- 2, because sequences: (4, 3, 4) and (4, 4, 2) have the same leader, whose value is 4.
The goal is to count the number of equi leaders. Write a function:
int solution(vector<int> &A);
that, given a non-empty zero-indexed array A consisting of N integers, returns the number of equi leaders.
For example, given:
A[0] = 4 A[1] = 3 A[2] = 4 A[3] = 4 A[4] = 4 A[5] = 2
the function should return 2, as explained above.
Assume that:
- N is an integer within the range [1..100,000];
- each element of array A is an integer within the range [−1,000,000,000..1,000,000,000].
Complexity:
- expected worst-case time complexity is O(N);
- expected worst-case space complexity is O(N), beyond input storage (not counting the storage required for input arguments).
Elements of input arrays can be modified.
// you can use includes, for example:
// #include
// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;
int solution(vector &A) {
// write your code in C++11
int size = 1;
int value = A[0];
for(unsigned int i=1;i(k+1)/2)&&((A.size()-k-1)/2<(cnt-leftCnt)))
res++;
}
return res;
}