Submission #1024426

#	Time	Username	Problem	Language	Result	Execution time	Memory
1024426		socpite	Jousting tournament (IOI12_tournament)	C++17	100 / 100	46 ms	20252 KiB

tournament

#include<bits/stdc++.h>
using namespace std;

const int maxn = 2e5+5;
const int INF = 1e9;

vector<int> g[maxn];
int FW[maxn];
int id[maxn], r[maxn], mn[maxn], A[maxn];

void add(int idx, int val){
	for(idx; idx < maxn; idx += idx&(-idx))FW[idx] += val;
}

int find_kth(int k){
	int pos = 0;
	for(int i = 17; i >= 0; i--){
		if((pos^(1<<i)) >= maxn)continue;
		if(k - FW[pos^(1<<i)] >= 0){
			pos^=(1<<i);
			k -= FW[pos];
		}
	}
	return pos+1;
}

int ans = -1, pos, tdfs = 0;

void pre_dfs(int x){
	mn[x] = INF;
	if(g[x].empty())tdfs++;
	for(int i = 0; i < g[x].size(); i++){
		pre_dfs(g[x][i]);
		mn[x] = min(mn[x], mn[g[x][i]]);
		if(i + 1 < g[x].size())mn[x] = min(mn[x], A[r[g[x][i]]]);
	}
	r[x] = tdfs;
}

void dfs(int x, int R, int dep, int dep_valid){
	if(mn[x] > R && dep_valid == -1)dep_valid = dep;
	if(g[x].empty() && dep - dep_valid > ans){
		ans = dep - dep_valid;
		pos = x;
	}
	for(auto v: g[x])dfs(v, R, dep+1, dep_valid);
}

int GetBestPosition(int N, int C, int R, int *K, int *S, int *E) {

	memset(FW, 0, sizeof(FW));
	for(int i = 0; i < maxn; i++)g[i].clear();

	for(int i = 1; i <= N; i++){
		id[i] = i;
		add(i, 1);
	}
	for(int i = 1; i < N; i++){
		A[i] = K[i-1];
		A[i] = N - A[i];
	}
	R = N - R;
	for(int i = 0; i < C; i++){
		N++;
		for(int _ = 0; _ < E[i] - S[i]; _++){
			int pos = find_kth(S[i]);
			g[N].push_back(id[pos]);
			add(pos, -1);
			id[pos] = 0;
		}
		int pos = find_kth(S[i]);
		g[N].push_back(id[pos]);
		id[pos] = N;
	}
	pre_dfs(N);
	dfs(N, R, 0, -1);
	return pos - 1;
}

Compilation message (stderr)

tournament.cpp: In function 'void add(int, int)':
tournament.cpp:12:6: warning: statement has no effect [-Wunused-value]
   12 |  for(idx; idx < maxn; idx += idx&(-idx))FW[idx] += val;
      |      ^~~
tournament.cpp: In function 'void pre_dfs(int)':
tournament.cpp:32:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |  for(int i = 0; i < g[x].size(); i++){
      |                 ~~^~~~~~~~~~~~~
tournament.cpp:35:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   35 |   if(i + 1 < g[x].size())mn[x] = min(mn[x], A[r[g[x][i]]]);
      |      ~~~~~~^~~~~~~~~~~~~

• Subtask 1: 17 / 17
• Subtask 2: 32 / 32
• Subtask 3: 51 / 51