Ratsun reitit

input/code.cpp: In function 'int main()':
input/code.cpp:30:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int i=0;i<pr.size();i++)
                     ~^~~~~~~~~~
input/code.cpp:46:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<r.size();i++)
                 ~^~~~~~~~~
input/code.cpp:48:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int j=0;j<r.size();j++) cout<<r[i][j]<<" ";
                     ~^~~~~~~~~

#include <bits/stdc++.h>
 
using namespace std;
 
int n;
vector<pair<int,int>> d={{2,1},{2,-1},{-2,1},{-2,-1},{1,2},{1,-2},{-1,2},{-1,-2}};
 
int main()
{
    cin>>n;
    vector<vector<int>> r;
    for(int y=0;y<n;y++)
    {
        vector<int> p;
        for(int x=0;x<n;x++)
        {
            p.push_back(1000);
        }
        r.push_back(p);
    }
    r[0][0]=0;
    vector<pair<int,int>> pr;
    pair<int,int> zr={0,0};
    pr.push_back(zr);
    int a=1;
    int l=1;
    while(a<n*n)
    {
        vector<pair<int,int>> nw;
        for(int i=0;i<pr.size();i++)
        {
            for(int j=0;j<8;j++)
            {
                pair<int,int> np={pr[i].first+d[j].first,pr[i].second+d[j].second};
                if(np.first>=0&&np.second>=0&&np.first<n&&np.second<n&&l<r[np.second][np.first])
                {
                    r[np.second][np.first]=l;
                    a++;
                    nw.push_back(np);
                }
            }
        }
        pr=nw;
        l++;
    }
    for(int i=0;i<r.size();i++)
    {
        for(int j=0;j<r.size();j++) cout<<r[i][j]<<" ";
        cout<<"\n";
    }
}

Test 1

Group: 1, 2, 3

Verdict: ACCEPTED

Test 2

Group: 1, 2, 3

Verdict: ACCEPTED

Test 3

Group: 1, 2, 3

Verdict: ACCEPTED

Test 4

Group: 1, 2, 3

Verdict: ACCEPTED

Test 5

Group: 1, 2, 3

Verdict: ACCEPTED

Test 6

Group: 1, 2, 3

Verdict: ACCEPTED

Test 7

Group: 1, 2, 3

Verdict: ACCEPTED

Test 8

Group: 2, 3

Verdict: ACCEPTED

Test 9

Group: 2, 3

Verdict: ACCEPTED

Test 10

Group: 2, 3

Verdict: ACCEPTED

Test 11

Group: 3

Verdict: ACCEPTED

Test 12

Group: 3

Verdict: ACCEPTED

Test 13

Group: 3

Verdict: ACCEPTED