Submission #1292972

#	Time	Username	Problem	Language	Result	Execution time	Memory
1292972		yf_yusuf	K-th path (IZhO11_kthpath)	C++20	0 / 100	1 ms	572 KiB

kthpath

//```//    YF YUSUF
#include <bits/stdc++.h>
// #include <iostream>
// #include <vector>
// #include <set>
// #include <map>
// #include <algorithm>
// #include <cmath>
// #include <numeric>
// #include <queue>
// #include <stack>
// #include <cassert>
// #include <climits>
// #include <string>
// #include <cstdlib>
// #include <random>
// #include <iomanip>
// #include <ctime>
using namespace std;
#ifdef YF_CHECK
	bool LOCAL = 1;
#else
	#pragma GCC optimize ("unroll-loops")
	#pragma GCC optimize ("inline")
	#pragma GCC optimize ("Ofast")
	#pragma GCC optimize ("O3")
	bool LOCAL = 0;
#endif
using ll   = long long;
using ld   = long double;
using vll  = vector <ll>;
using mll  = map <ll,ll>;
using pll  = pair <ll,ll>;
using vvl  = vector <vll>;
using vpll = vector <pll>;
template<class T>T MIN(T&a,T b){a=min(a,b);return a;}
template<class T>T MAX(T&a,T b){a=max(a,b);return a;}
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define sgr v+v+1,(tl+tr)/2+1,tr
#define sgl v+v,tl,(tl+tr)/2
#define pb push_back
#define ins insert
#define S second
#define F first
mt19937_64 MT(time(0));
ll BP(ll a,ll b,ll mod=1e9+7){
	if(b==0)return 1;
	ll q=BP(a,b/2,mod);
	return ((q*q)%mod*(b%2?a:1ll))%mod;
}
ll f(ll x){return x*(x+1)/2;}
ll dup(ll a,ll b){return (a+b-1)/b;}
ll lcm(ll a,ll b){return a/__gcd(a,b)*b;}
ll invf(ll x){return (-1+sqrt(1+8*x))/2;}
ll lg(ll x){return (x ? 63 - __builtin_clzll(x) : -1);}
const ll  mod=998244353;
const ll  INF=1e18;
const ll  inf=1e9+7;
const ll  N  =1e6+7;
ll slow_cnk(ll n,ll k){
	MIN(k, n-k);
  ll ans = 1;
  for (int i = 1; i <= k; i++) 
  	ans = (ans * (n-k+i) / i);
  return ans;
}
ll get(ll n,ll m){
	return slow_cnk(n+m-2, min(n-1, m-1));
}
ll n, m, k;
ll GET(ll i,ll j){
	return get(n-i+1, m-j+1);
}
void YF_MAIN(ll TEST){
	cin>>n>>m;
	string s[n];
	for(int i=0;i<n;i++)
		cin>>s[i];
	while(cin>>k){
		ll i=0, j=0;
		string ans;ans+=s[i][j];
		while(i < n-1 && j < m-1){
			ll A = GET(1+i+1, 1+j);
			ll B = GET(1+i, 1+j+1);
			// cout<<i<<" "<<j<<": "<<A<<" "<<B<<" "<<k<<"\n";
			if(s[i+1][j] < s[i][j+1]){
				if(A >= k){
					i++;
					// j++;
				} else{
					k -= A;
					j++;
					// i++;
				}
			}
			else{
				if(B >= k){
					j++;
					// i++;
				} else{
					k-=B;
					i++;
					// j++;
				}
			}
			ans += s[i][j];
		}
		while(j<m-1){
			j++;
			ans+=s[i][j];
		}
		while(i<n-1){
			i++;
			ans+=s[i][j];
		}
		cout<<ans<<"\n";
	}
}
const bool TECT=0;
const bool FLSH=0;
const ll SN=1e0 + 7; ll SM[SN];
const ll FN=1e0 + 7; ll FACT[FN], inv[FN], FMOD=inf;
ll PNK(ll n,ll k){return FACT[n] *inv[n-k]%FMOD;}
ll CNK(ll n,ll k){return PNK(n,k)*inv[k  ]%FMOD;}
void BEFORE(){
	for(ll i=2;i<SN;i++){
		if(SM[i])continue;
		for(ll j=i;j<SN;j+=i)
			MAX(SM[j],i);
	}
	FACT[0]=inv[0]=1;
	for(int i=1;i<FN;i++){
		FACT[i]=FACT[i-1]*i%FMOD;
		inv[i]=BP(FACT[i],FMOD-2,FMOD);
	}
}
signed main(){
	// freopen(("input.txt"),"r",stdin);freopen(("output.txt"),"w",stdout);
	if(FLSH){
		ios_base::sync_with_stdio(0);
		cout.setf(ios::fixed);
		cout.precision(0);
		cout.tie(0);
		cin.tie(0);
	}
	int TEST=1;
	if(TECT)
		cin>>TEST;
	BEFORE();
	for(int T=1;T<=TEST;T++){
		// cout<<"Case "<<T<<": ";
		YF_MAIN(T);
		cout<<(T==TEST ? "" : "\n");
	}
	return 0;
} 
//   YF YUSUF ```

• Subtask 1: 0 / 100