Submission #1034995

#	Time	Username	Problem	Language	Result	Execution time	Memory
1034995		pcc	Homework (CEOI22_homework)	C++17	100 / 100	247 ms	151104 KiB

Main

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

#pragma GCC optimize("O3,unroll-loops")

const int mxn = 1e6+10;
vector<int> tree[mxn*2];
int val[mxn*2],dp[mxn*2];
int vcnt = 0;
int N;
string s;
int rt;

void dfs(int now){
	for(auto nxt:tree[now])dfs(nxt);
	dp[now] = 0;
	if(val[now] == -1)dp[now] = min(dp[tree[now][0]],dp[tree[now][1]]);
	else if(val[now] == -2)dp[now] = dp[tree[now][0]]+dp[tree[now][1]]+1;
	return;
}

int main(){
	ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
	cin>>s;
	for(int i = 0;i<s.size();i++)N += s[i] == '?';
	{
		int pt = 0;
		vector<int> v,stk;
		while(pt<s.size()){
			if(s[pt] == 'm'){
				if(s.substr(pt,3) == "min"){
					v.push_back(-1);
				}
				else{
					v.push_back(-2);
				}
				pt += 3;
			}
			else if(s[pt] == '?'){
				v.push_back(++vcnt);
				pt++;
			}
			else pt++;
		}
		vcnt = N;
		for(auto &i:v){
			stk.push_back(i);
			while(stk.size()>=2&&stk.end()[-1]>0&&stk.end()[-2]>0){
				int a = stk.end()[-1],b = stk.end()[-2];
				stk.pop_back();stk.pop_back();
				int c = ++vcnt;
				tree[c].push_back(a);
				tree[c].push_back(b);
				assert(stk.back()<0);
				val[c] = stk.back();
				stk.pop_back();
				rt = c;
				stk.push_back(c);
			}
		}
	}
	/*
	for(int i = 1;i<=vcnt;i++){
		if(val[i])cerr<<i<<' '<<val[i]<<":"<<tree[i][0]<<','<<tree[i][1]<<endl;
	}
	*/
	dfs(rt);
	int l = dp[rt];
	//for(int i = 1;i<=vcnt;i++)cerr<<dp[i]<<',';cerr<<endl;
	for(int i = 1;i<=vcnt;i++)if(val[i] < 0)val[i] = (val[i] == -2?-1:-2);
	/*
	for(int i = 1;i<=vcnt;i++){
		if(val[i])cerr<<i<<' '<<val[i]<<":"<<tree[i][0]<<','<<tree[i][1]<<endl;
	}
	*/
	dfs(rt);
	//for(int i = 1;i<=vcnt;i++)cerr<<dp[i]<<',';cerr<<endl;
	int r = N-dp[rt]-1;
	cout<<max(0,r-l+1)<<'\n';
	return 0;
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:25:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   25 |  for(int i = 0;i<s.size();i++)N += s[i] == '?';
      |                ~^~~~~~~~~
Main.cpp:29:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   29 |   while(pt<s.size()){
      |         ~~^~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 13 / 13
• Subtask 3: 13 / 13
• Subtask 4: 30 / 30
• Subtask 5: 34 / 34