Submission #336985

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
336985	2020-12-17T16:27:52 Z	gs14004	Archery (IOI09_archery)	C++17	100 / 100	245 ms	10556 KB

archery

#include <bits/stdc++.h>
#define sz(v) ((int)(v).size())
#define all(v) (v).begin(), (v).end()
using namespace std;
using lint = long long;
using pi = pair<int, int>;
const int MAXN = 400005;
const int mod = 1e9 + 7;
 
int n, r, a[MAXN], b[MAXN];
int cnt[MAXN][3];
 
int Do(int r, int s){
	if(s == 1) return 0;
	memset(cnt, 0, sizeof(cnt));
	auto mode = [&](int x){
		if(x < s) return 0;
		if(x == s) return 1;
		return 2;
	};
	if(s > n + 1){
		int myOrig = -1;
		for(int i = 0; i < n; i++){
			int pos = i;
			if(pos == 0) pos = n - 1;
			if(a[i] > n + 1) cnt[pos][mode(a[i])]++;
			if(a[i+n] > n + 1) cnt[pos][mode(a[i+n])]++;
			if(a[i] == s) myOrig = i;
			if(a[i+n] == s) myOrig = i;
		}
		pi minp(0, n-1);
		int cur = 0;
		for(int i=n-1; i>=1; i--){
			cur += cnt[i][0] + cnt[i][1] + cnt[i][2] - 1;
			minp = max(minp, pi(-cur, i-1));
		}
		int cand[3] = {};
		vector<int> reside(n);
		for(int i = 0; i < n - 1; i++){
			int pos = minp.second - i + 2 * (n-1) - 1;
			pos %= n - 1;
			pos += 1;
			for(int j=0; j<3; j++) cand[j] += cnt[pos][j];
			int ptr = 2;
			while(ptr >= 0 && !cand[ptr]) ptr--;
			assert(ptr >= 0);
			cand[ptr]--;
		//	printf("%d %d\n", pos, ptr);
			reside[pos] = ptr;
		}
		int myPos = find(all(reside), 1) - reside.begin();
		assert(myPos < n);
		int rotated = (myPos > myOrig); 
		return myPos - rotated * n;
	}
	else{
		for(int i = 0; i < n; i++){
			cnt[i][mode(a[i])]++;
			cnt[i][mode(a[i + n])]++;
		}
		int winner = 0;
		int rotated = 0;
		while(!cnt[0][winner]) winner++;
		cnt[0][winner]--;
		int cand[3] = {};
		for(int i = 1; i <= 3 * n; i++){
			for(int j=0; j<3; j++){
				cand[j] += cnt[(i-1)%n][j];
				cnt[(i-1)%n][j] = 0;
			}
			int loser = 0;
			while(!cand[loser]) loser++;
			cand[loser]--;
			if(winner > loser) swap(winner, loser);
			// deport loser after round i
			cnt[(i-1)%n][loser]++;
			if(loser == 1){
				rotated++;
				if(i > 2 * n){
					int will_move = (r + n - i) % n;
					if(r < i) rotated--;
					return (n - 1 - will_move) % n - (rotated) * n;
				}
			}
		}
		assert(0);
	}
	int rot = 0;
	for(int i=0; i<r; i++){
		for(int j=0; j<n; j++){
			if(a[j] > a[j+n]) swap(a[j], a[j+n]);
		}
		swap(a[0], a[n]);
		if(a[0] == s) rot++;
		rotate(a, a + 1, a + n);
	}
	int pos = (find(a, a + 2 * n, s) - a) % n - rot * n;
	return pos;
}
 
mt19937 rng(0x14004);
 
int main(){
	scanf("%d %d",&n,&r);
	for(int i=0; i<2*n; i++){
		scanf("%d",&b[i]);
	}
	r = (r % n) + 2 * n;
	int s = 0, e = n - 1;
	auto fn = [&](int i){
		vector<int> foo(b, b + 2 * n);
		rotate(foo.begin(), foo.begin() + 1, foo.begin() + 2 * i + 1);
		for(int i=0; i<n; i++){
			a[i] = foo[2*i];
			a[i+n] = foo[2*i+1];
		}
		return Do(r, b[0]);
	};
//	for(int i=0; i<n; i++) printf("%d ", fn(i));
	auto Mod = [&](int x){ return (x % n + n) % n; };
	int qq = fn(n - 1);
	while(s != e){
		int m = (s + e) / 2;
		if(fn(m) >= qq - Mod(qq)) e = m;
		else s = m + 1;
	}
	int rr = fn(s);
	s = 0, e = n - 1;
	while(s != e){
		int m = (s + e + 1) / 2;
		if(fn(m) <= rr) s = m;
		else e = m - 1;
	}
	cout << s + 1 << endl;
}

Compilation message

archery.cpp: In function 'int main()':
archery.cpp:104:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  104 |  scanf("%d %d",&n,&r);
      |  ~~~~~^~~~~~~~~~~~~~~
archery.cpp:106:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  106 |   scanf("%d",&b[i]);
      |   ~~~~~^~~~~~~~~~~~

Subtask #1

6.0 / 6.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	364 KB	Output is correct
2	Correct	1 ms	364 KB	Output is correct
3	Correct	6 ms	4972 KB	Output is correct
4	Correct	10 ms	5100 KB	Output is correct
5	Correct	5 ms	4972 KB	Output is correct
6	Correct	6 ms	4972 KB	Output is correct

Subtask #2

94.0 / 94.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	6 ms	4972 KB	Output is correct
2	Correct	6 ms	4972 KB	Output is correct
3	Correct	9 ms	5100 KB	Output is correct
4	Correct	29 ms	5356 KB	Output is correct
5	Correct	245 ms	9144 KB	Output is correct
6	Correct	7 ms	4972 KB	Output is correct
7	Correct	8 ms	5100 KB	Output is correct
8	Correct	26 ms	5376 KB	Output is correct
9	Correct	30 ms	5576 KB	Output is correct
10	Correct	9 ms	5120 KB	Output is correct
11	Correct	33 ms	5572 KB	Output is correct
12	Correct	10 ms	5100 KB	Output is correct
13	Correct	164 ms	8100 KB	Output is correct
14	Correct	13 ms	5100 KB	Output is correct
15	Correct	49 ms	5872 KB	Output is correct
16	Correct	6 ms	4972 KB	Output is correct
17	Correct	8 ms	5100 KB	Output is correct
18	Correct	9 ms	5100 KB	Output is correct
19	Correct	11 ms	5100 KB	Output is correct
20	Correct	13 ms	5100 KB	Output is correct
21	Correct	31 ms	5572 KB	Output is correct
22	Correct	38 ms	5756 KB	Output is correct
23	Correct	214 ms	9196 KB	Output is correct
24	Correct	6 ms	4972 KB	Output is correct
25	Correct	8 ms	5100 KB	Output is correct
26	Correct	13 ms	5100 KB	Output is correct
27	Correct	39 ms	5612 KB	Output is correct
28	Correct	183 ms	8596 KB	Output is correct
29	Correct	9 ms	5100 KB	Output is correct
30	Correct	16 ms	5100 KB	Output is correct
31	Correct	28 ms	5612 KB	Output is correct
32	Correct	198 ms	9772 KB	Output is correct
33	Correct	7 ms	4972 KB	Output is correct
34	Correct	7 ms	4972 KB	Output is correct
35	Correct	10 ms	5100 KB	Output is correct
36	Correct	15 ms	5100 KB	Output is correct
37	Correct	24 ms	5484 KB	Output is correct
38	Correct	31 ms	5740 KB	Output is correct
39	Correct	6 ms	4972 KB	Output is correct
40	Correct	8 ms	5100 KB	Output is correct
41	Correct	9 ms	5100 KB	Output is correct
42	Correct	10 ms	5100 KB	Output is correct
43	Correct	14 ms	5100 KB	Output is correct
44	Correct	16 ms	5356 KB	Output is correct
45	Correct	26 ms	5612 KB	Output is correct
46	Correct	29 ms	5612 KB	Output is correct
47	Correct	212 ms	10556 KB	Output is correct