Submission #683522

#	Time	Username	Problem	Language	Result	Execution time	Memory
683522		Ronin13	Chessboard (IZhO18_chessboard)	C++14	47 / 100	186 ms	3380 KiB

chessboard

#include <bits/stdc++.h>
#define ll long long
#define ull unsigned ll
#define f first
#define s second
#define pii pair<ll,ll>
#define pll pair<ll,ll>
#define pb push_back
#define epb emplace_back
using namespace std;
/*
6 8
3 3 3 3
1 2 1 2
3 4 3 4
5 5 5 5
4 3 4 3
4 4 4 4
2 1 2 1
3 6 3 6
*/

int pos[100001][2];

ll compute_line(ll x1, ll y1, ll x2, ll y2, ll k){
    ll u = (x1 / k + y1 / k);
    ll v = (x2 / k + y2 / k);
    ll a = (x2 - x1 + 1);
    ll b = (y2 - y1 + 1);
    ll cnt = 0;
    if(u % 2 == v % 2){
        if(u & 1){
            cnt +=  k * a;
        }
        else cnt -= k * a;
    }
    ll c = k - (y2 % k);
    if(u & 1){
        cnt -= c * a;
    }
    else cnt += c * a;
    ll d = y1 % k;
    d++;
    if(v & 1) cnt -= d * a;
    else cnt += d * a;
    return cnt;
}

ll C(ll x1, ll y1, ll x2, ll y2, ll k){
    if((x1 / k) == (x2 / k)){
        if((y1 / k) == (y2 / k)){
            ll x = x1 / k + y1 / k;
            if(x % 2) return 0-(x2 - x1 + 1) * (y2 - y1 + 1);
            return (x2 - x1 + 1) * (y2 - y1 + 1);
        }
        return compute_line(x1, y1, x2, y2, k);
    }
    if(y1 / k == y2 / k)
        return compute_line(y1, x2, y2, x2, k);
    ll cnt = 0;
    cnt += compute_line(x1, y1, x1 / k * k + (k - 1), y2, k);
    cnt += compute_line(x2 / k * k, y1, x2, y2, k);
    ll v = x2 / k;
    v -= x1 / k;
    v--;
    if(v){
        ll j = x1 / k * k + k;
        ll nw = compute_line(j, y1, j + k, y2, k);
        if(v & 1) cnt += nw;
    }
    return cnt;
}

int main(){
  //  freopen("school.in", "r", stdin);
 // freopen("school.out", "w", stdout);
    ll n, k;
    cin >> n >> k;
    ll x1[k + 1], x2[k + 1], y1[k + 1], y2[k + 1];
    for(int i =  1; i <= k; ++i){
        cin >> x1[i] >> y1[i] >> x2[i] >> y2[i];
        x1[i]--;
        y1[i]--;
        x2[i]--;
        y2[i]--;
    }
    ll ans = 1e18 + 1;
    for(int a = 1; a <n; a++){
        if(n % a) continue;
        ll v = n / a;
        ll cnt = 0;
        if(v % 2 == 1)
            cnt += v * (v / 2) + (v + 1)  / 2;
        else cnt = v * v / 2;
        cnt *= a * a;
        for(int i = 1; i <= k; i++){
            cnt -= C(x1[i], y1[i], x2[i], y2[i], a);
        }
        ans = min(ans, cnt);
    }
    for(ll a = 1; a <n; a++){
        if(n % a) continue;
        ll v = n / a;
        ll cnt = -1;
        if(v % 2 == 1)
            cnt += v * (v / 2) + (v + 1) / 2;
        else cnt = v * v / 2;
        cnt *= a * a;
        for(int i = 1; i <= k; i++)
            cnt += C(x1[i], y1[i], x2[i], y2[i], a);
        ans = min(ans, cnt);
    }
    cout << ans;
    return 0;
}

Compilation message (stderr)

chessboard.cpp: In function 'long long int compute_line(long long int, long long int, long long int, long long int, long long int)':
chessboard.cpp:29:8: warning: unused variable 'b' [-Wunused-variable]
   29 |     ll b = (y2 - y1 + 1);
      |        ^

• Subtask 1: 8 / 8
• Subtask 2: 8 / 8
• Subtask 3: 15 / 15
• Subtask 4: 16 / 16
• Subtask 5: 0 / 23
• Subtask 6: 0 / 30