CSES - Datatähti 2022 alku - Results
Submission details
Task:Spiraali
Sender:xenial
Submission time:2021-10-05 20:08:01
Language:C++17
Status:READY
Result:100
Feedback
groupverdictscore
#1ACCEPTED15
#2ACCEPTED20
#3ACCEPTED65
Test results
testverdicttimegroup
#1ACCEPTED0.01 s1details
#2ACCEPTED0.01 s2details
#3ACCEPTED0.01 s3details

Compiler report

input/code.cpp: In function 'void set_io(std::__cxx11::string)':
input/code.cpp:16:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
         freopen((filename + ".in").c_str(), "r", stdin);
         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
input/code.cpp:17:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
         freopen((filename + ".out").c_str(), "w", stdout);
         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
input/code.cpp: In function 'int main()':
input/code.cpp:65:13: warning: 'start' may be used uninitialized in this function [-Wmaybe-uninitialized]
         ans += (rindex - 1) * (base + base - (rindex - 2) * 8) / 2;
         ~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Code

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define all(x) (x).begin(), (x).end()
#define pb push_back
#define fi first
#define se second
#define sz size
#define rsz resize

void set_io(string filename = "") {
    ios::sync_with_stdio(0);
	cin.tie(0);

    if (filename != "") {
        freopen((filename + ".in").c_str(), "r", stdin);
        freopen((filename + ".out").c_str(), "w", stdout);
    }
}

int main() {
    set_io("");

    ll n, t; cin >> n >> t; 
    ll mid = n / 2;
    
    while (t--) {
        ll y, x; cin >> y >> x;
        ll xdist = n - x + 1;
        ll ydist = n - y + 1;
        ll ring = 4 * (n - 1), rindex = min(min(x, xdist), min(y, ydist)), dx, dy, offset;

        if (x <= mid) {
            if (y <= mid) {
                dx = x - min(x, y) + 1; dy = y - min(x, y) + 1;
                if (dx != 1) offset = -8;
                else offset = 0;
            } else {
                offset = -2;
                dx = x - min(x, ydist) + 1; dy = y + min(x, ydist) - 1;
            }
        } else {
            if (y <= mid) {
                offset = -6;
                dx = x + min(xdist, y) - 1; dy = y - min(xdist, y) + 1;
            } else {
                offset = -4;
                dx = x + min(xdist, ydist) - 1; dy = y + min(xdist, ydist) - 1;
            }
        }

        ll start;
        if (dx == 1) {
            start = dy;
        } else if (dx == n) {
            start = 2 * n + n - 1 - dy;
        } else if (dy == 1) {
            start = ring + 2 - dx;
        } else if (dy == n) {
            start = n - 1 + dx;
        }

        ll base = ring + offset;
        ll ans = start;
        ans += (rindex - 1) * (base + base - (rindex - 2) * 8) / 2;

        cout << ans << endl;
    }
}

Test details

Test 1

Group: 1

Verdict: ACCEPTED

input
10 100
1 1
1 2
1 3
1 4
...

correct output
1
36
35
34
33
...

user output
1
36
35
34
33
...

Test 2

Group: 2

Verdict: ACCEPTED

input
1000 1000
371 263
915 322
946 880
53 738
...

correct output
773533
312166
206053
200080
593922
...

user output
773533
312166
206053
200080
593922
...

Test 3

Group: 3

Verdict: ACCEPTED

input
1000000000 1000
177757853 827347032
409613589 419171337
739269360 256524697
328695530 896842209
...

correct output
571375684522141210
967321186816598569
762879105851175000
370065046779516790
936897883750373771
...

user output
571375684522141210
967321186816598569
762879105851175000
370065046779516790
936897883750373771
...