Implementation of C ++ code with a limited period of job scheduling improvement

Algorithm idea: the
three arrays are the value of the job p [i], the time d [i], the most recent previous insertable job f [i], and the parent [i] whose initial value is -1
will be output The result is saved in std :: vector <int> res
First sorted according to p [i], every time you use greedy to find the largest p [i] value, you can
traverse the array from 1 to determine whether d [i] meets the conditions
Judgment method:
find the root j through the find method, which is the closest possible insertion point, and then judge whether f [j] can be inserted, if it cannot be inserted, discard it, otherwise save i in res and then put Union in front The nearest root and this value

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int parent[1005], d[1005] = {0, 2, 2, 1, 3, 3}, f[1005];

void unionArray(int i, int j) {
    int x = parent[i] + parent[j];
    if(parent[i] > parent[j]) { // i的节点少
        parent[i] = j;
        parent[j] = x;
    } else {
        parent[j] = i;
        parent[i] = x;
    }
}

int find(int i) {
    int j = i;
    while (parent[j] > 0) {
        j = parent[j];
    }
    int k = i;
    while (parent[k] > 0) {
        int temp = parent[k];
        parent[k] = j;
        k = temp;
    }
    return j;
}

int main() {
    int size = 5;
    vector<int> res;
    for (int i = 0; i <= size; ++i) {
        parent[i] = -1;
        f[i] = i;
    }
    for (int i = 1; i <= size; ++i) {
        int j = find(min(size, d[i]));
        if(f[j]!= 0) {
            res.push_back(i);
            int l = find(f[j]-1);
            unionArray(l, j);
            f[j] = f[l];
        }
        for (int k = 0; k <= size; ++k) {
            cout << f[k] << ends;
        }
        cout << endl;
    }
    for (int re : res) {
        cout << re << ends;
    }
    return 0;
}