928B - Chat - CodeForces Solution

#include <iostream>
#include <string.h>
#include <algorithm>
using namespace std;

int main(){
    int n,k;
    cin >> n >> k;

    int inds[n + 1];
    for (int i = 1; i <= n; i++){
        cin >> inds[i];
    }

    int reads[n + 1];
    memset(reads, 0, sizeof(reads));
    for (int i = 1; i <= n; i++){
        int prev = inds[i];
        int l = max(1, prev - k);
        int curl = max(1, i - k);
        int r = min(n, prev + k);
        int curr = min(n, i + k);

        if (prev == 0){
            reads[i] = (curr - curl + 1);
            continue;
        }

        if (curl > r){
            reads[i] = (curr - curl + 1) + reads[prev];
        }
        else{
            int diff = curr - r;
            reads[i] = diff + reads[prev];
        }
    }

    for (int i = 1; i <= n; i++){
        cout << reads[i] << " ";
    }
}