[codility]Perm-Check

// you can also use includes, for example:
// #include <algorithm>
int solution(vector<int> &A) {
    // write your code in C++98
    //...modify the input array, let all the elements in the right place
    for(int i = 0; i < A.size(); ++i)
    {
        int curIdx = A[i]-1;
        while(curIdx >= 0 && curIdx < A.size() && A[curIdx] != curIdx+1)
        {
            int nextIdx = A[curIdx]-1;
            A[curIdx] = curIdx+1;
            curIdx = nextIdx;
        }
    }
    //...check if it's a permutation now
    for(int i = 0; i < A.size(); ++i)
        if(A[i] != i+1) return 0;
    return 1;
}