first Missing Positive number



classSolution {

public:

int firstMissingPositive(intA[],intn) {

for (int index = 0; index<n; index++)

{

while (A[index]>0 && A[index] != index + 1 && A[index] <= n && A[index] != A[A[index] - 1])

{

int temp = A[index];

A[index] = A[temp - 1];

A[temp - 1] = temp;

}

}

for (int index = 0; index<n; index++)

{

if (A[index] != index + 1) return index + 1;

}

returnn + 1;

}

};