Submission #337912

#	Time	Username	Problem	Language	Result	Execution time	Memory
337912		tengiz05	K-th path (IZhO11_kthpath)	C++17	0 / 100	1 ms	364 KiB

kthpath

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define FASTIO ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
#define all(x) (x).begin(), (x).end()
#define pb push_back
#define pii pair<int, int>
#define ff first
#define ss second
#define PI acos(-1)
#define ld long double
template <class T> bool ckmin(T& a, const T& b) {return a > b ? a = b, true : false;}
template <class T> bool ckmax(T& a, const T& b) {return a < b ? a = b, true : false;}
const int mod = 1e9+7, N = 1005;
int msb(int val){return sizeof(int)*8-__builtin_clzll(val);}
int n, m, k;
char a[N];
string S[N];
int dp[N];
vector<int> edges[N];
bool used[N];
string ans;
void dps(int u){
	used[u] = true;
	string mx = "A";
	S[u] += a[u];
	if(edges[u].empty()){
		dp[u] = 1;
		return;
	}
	for(auto v : edges[u]){
		if(!used[v])dps(v);
		dp[u] += dp[v];
		mx = max(mx, S[v]);
	}
	S[u] += mx;
}

void dfs(int u){
	ans.pb(a[u]);
	if(edges[u].size() == 0)return;
	if(edges[u].size() == 1){
		dfs(edges[u][0]);
	}else if(edges[u].size() == 2){
		if(S[edges[u][0]] > S[edges[u][1]])swap(edges[u][0], edges[u][1]);
		int f = edges[u][0];
		int s = edges[u][1];
		if(dp[f] >= k)dfs(f);
		else{
			k -= dp[f];
			dfs(s);
		}
	}else assert(false);
}

void solve(int test_case){
	int i, j;
	cin >> n >> m;
	for(i=0;i<n;i++){
		for(j=0;j<m;j++){
			cin >> a[i*m+j];
			if(i+1<n){
				edges[i*m+j].pb((i+1)*m+j);
			}
			if(j+1 < m){
				edges[i*m+j].pb(i*m+j+1);
			}
		}
	}
	dps(0);
/*	for(i=0;i<n;i++){
		for(j=0;j<m;j++){
			cout << S[i*m+j] << ' ';
		}cout << '\n';
	}*/
	cin >> k;
//	memset(used, 0, sizeof(used));
	dfs(0);
	cout << ans << '\n';
	return;
}

signed main(){
	FASTIO;
#define MULTITEST 0
#if MULTITEST
	int _T;
	cin >> _T;
	for(int T_CASE = 1; T_CASE <= _T; T_CASE++)
		solve(T_CASE);
#else
	solve(1);
#endif
	return 0;
}

• Subtask 1: 0 / 100