Submission #728900

#	Time	Username	Problem	Language	Result	Execution time	Memory
728900		shadow_sami	Tracks in the Snow (BOI13_tracks)	C++17	100 / 100	973 ms	251980 KiB

tracks

#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;
typedef long long int ll;
typedef vector<ll> vi;
typedef vector<vector<ll>> vvi;
typedef pair<ll,ll> pi;
typedef map<ll,ll> mi;
typedef long double ld;
typedef vector<ld> vd;
typedef vector<vector<ld>> vvd;
typedef pair<ld,ld> pd;
#define ff first
#define ss second
#define srt(a) sort(a.begin(),a.end());
#define fip(k, n) for (ll i = k; i < n; i++)
#define fjp(k, n) for (ll j = k; j < n; j++)
#define fin(k, n) for (ll i = k; i >= n; i--)
#define fjn(k, n) for (ll j = k; j >= n; j--)
#define fp(k, n, m) for (ll k = n; k < m; k++)
#define fn(k, n, m) for (ll k = n; k >= m; k--)
#define ordered_set tree<pi, null_type,less< pi >, rb_tree_tag,tree_order_statistics_node_update>
#define totalOne(n) __builtin_popcount(n)
#define backZero(n) __builtin_ctzll(n)
#define frontZero(n) __builtin_clzll(n)
#define fx(k) for ( auto x : k )
#define test ll t;cin >> t;while (t--)
#define nli "\n"

// ==========================(debug)============================================================================================== //

#ifndef ONLINE_JUDGE
#define debug(x) cerr << #x <<" "; _printn(x); cerr << nli;
#else
#define debug(x)
#endif

void _printn(ll x){ cerr<<x<<" "; }
void _printn(int x){ cerr<<x<<" "; }
void _printn(ld x){ cerr<<x<<" "; }
void _printn(double x){ cerr<<x<<" "; }
void _printn(string x){ cerr<<x<<" "; }
void _printn(char x){ cerr<<x<<" "; }
void _printn(bool x){ cerr<<x<<" "; }
template<class T,class V>void _printn(pair<T,V> vv);
template<class T> void _printn(vector<T> vv);
template<class T> void _printn(set<T> vv);
template<class T,class V> void _printn(map<T,V> vv);
template<class T> void _printn(multiset<T> vv);
template<class T,class V>void _printn(pair<T,V> vv){ cerr<<"( ";_printn(vv.ff);cerr<<",";_printn(vv.ss);cerr<<")";}
template<class T> void _printn(vector<T> vv){ cerr<<"[ "; for(auto xx:vv){ _printn(xx);cerr<<" "; } cerr<<"]"; };
template<class T> void _printn(set<T> vv){ cerr<<"{ "; for(auto xx:vv){ _printn(xx);cerr<<" "; } cerr<<"}"; };
template<class T> void _printn(multiset<T> vv){ cerr<<"{ "; for(auto xx:vv){ _printn(xx);cerr<<" "; } cerr<<"}"; };
template<class T,class V> void _printn(map<T,V> vv){ cerr<<"{ "; for(auto xx:vv){ _printn(xx);cerr<<" "; } cerr<<"}"; };

// ==========================(debug)============================================================================================== //

ll n,m,tp,tp2,res,cnt,sum,tptp,ans;
const ll mx = 4000+5;
const ll mod = 1e9+7;

// ==========================(MOD)=============================================================================================== //

ll mod_add(ll aa,ll bb){ return ((aa%mod)+(bb%mod))%mod; }
ll mod_minus(ll aa,ll bb){ return (((aa%mod)-(bb%mod))+10*mod)%mod; }
ll mod_mul(ll aa,ll bb){ return ((aa%mod)*(bb%mod))%mod; }
ll mod_power(ll aa,ll bb){ aa%=mod; ll empowered = 1; bb%=mod-1; while(bb > 0){ if(bb & 1) empowered = mod_mul(empowered,aa); bb = bb >> 1; aa = mod_mul(aa,aa); } return empowered; }
ll mod_divi(ll aa,ll bb){ aa=mod_mul(aa,mod_power(bb,mod-2)); return aa; }

// ==========================(MOD)=============================================================================================== //

bool f = false;
ll dx[4] = {0,1,0,-1};
ll dy[4] = {1,0,-1,0};
deque<pi> dq;
char a[mx][mx];
ll tnc[mx][mx];

bool meow(ll x,ll y){
	if(x < 0 || x >= n)
		return 0;
	if(y < 0 || y >= m)
		return 0;
	if(a[x][y] == '.')
		return 0;
	return 1;
}

int main(){
    ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    // #ifndef ONLINE_JUDGE
    //     freopen("input1.txt", "r", stdin);
    //     freopen("output1.txt", "w", stdout);
    //     freopen("error1.txt", "w", stderr);
    // #endif // ONLINE_JUDGE

        cin>>n>>m;
        fip(0,n)
        	fjp(0,m)
        		cin>>a[i][j];
        memset(tnc,0ll,sizeof(tnc));
        dq.push_front({0,0});
        ans = 0;
        tnc[0][0] = 1;
        while(dq.size()){
        	auto it = dq.front();
        	dq.pop_front();
        	ans = max(ans,tnc[it.ff][it.ss]);
        	fip(0,4){
        		ll x = it.ff + dx[i];
        		ll y = it.ss + dy[i];
        		if(meow(x,y) && tnc[x][y]==0){
        			if(a[x][y]==a[it.ff][it.ss]){
        				tnc[x][y] = tnc[it.ff][it.ss];
        				dq.push_front({x,y});
        			}else{
        				tnc[x][y] = tnc[it.ff][it.ss] + 1;
        				dq.push_back({x,y});
        			}        			
        		}
        	}
        }
        cout<<ans<<nli;
        
    // cerr << "Time elapsed: " << setprecision(6) << 1000.0 * clock() / CLOCKS_PER_SEC << "ms\n";
    return 0;
}

• Subtask 1: 30 / 30
• Subtask 2: 70 / 70