Submission #1255320

#	Time	Username	Problem	Language	Result	Execution time	Memory
1255320		Mer123haba456	Tracks in the Snow (BOI13_tracks)	C++20	100 / 100	1970 ms	303284 KiB

tracks

#include <bits/stdc++.h>
using namespace std;
#define fast_io ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
#define N lli(4005)
#define MOD lli(1e9 + 7)
#define heps(v) v.begin(), v.end()
typedef long long int lli;
typedef vector<lli> vlli;
typedef pair<lli, lli> plli;
typedef vector<plli> vplli;
typedef pair<lli, plli> pplli;
typedef vector<pplli> vpplli;

lli n,m,k,q,t;
vlli vect;

lli diz[N][N];

lli vis[4002][4002];

vplli yonler = {{0,1},{0,-1}, {1,0}, {-1,0}};

int main()
{
    scanf("%lld %lld", &n, &m);
    for(lli i = 1;i<=n;i++)
        for(lli j = 1;j<=m;j++){
            char c;
            scanf(" %c", &c);
            //cin >> c;
            if(c == 'F')
                diz[i][j] = 1;
            else if(c == 'R')
                diz[i][j] = 2;
        }
    queue<pplli> R;
    queue<pplli> F;
    R.push({1, {1,1}});
    bool hang = 0;
    lli enb = 0;
    while(!(R.empty()) || !(F.empty())){
        if(R.empty())
            hang = 1;
        else if(F.empty())
            hang = 0;
        pplli su = {0,{0,0}};
        if(hang){
            su = F.front();
            F.pop();
        }else{
            su = R.front();
            R.pop();
        }
        if(vis[su.second.first][su.second.second])
            continue;
        vis[su.second.first][su.second.second] = 1;
        enb = max(enb, su.first);
        for(plli yon : yonler){
            lli x = su.second.first + yon.first;
            lli y = su.second.second + yon.second;
            if(vis[x][y])
                continue;
            if(!diz[x][y])
                continue;
            if(diz[x][y] == diz[su.second.first][su.second.second]){
                if(hang)
                    F.push({su.first, {x,y}});
                else
                    R.push({su.first, {x,y}});
            }else{
                if(hang)
                    R.push({su.first + 1, {x,y}});
                else
                    F.push({su.first + 1, {x,y}});
            }
        }
    }
    printf("%lld", enb);
}

Compilation message (stderr)

tracks.cpp: In function 'int main()':
tracks.cpp:25:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   25 |     scanf("%lld %lld", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~
tracks.cpp:29:18: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   29 |             scanf(" %c", &c);
      |             ~~~~~^~~~~~~~~~~

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