Submission #31344

#	Time	Username	Problem	Language	Result	Execution time	Memory
31344		imaxblue	Tracks in the Snow (BOI13_tracks)	C++14	84.69 / 100	2000 ms	63188 KiB

tracks

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define mp make_pair
#define pb push_back
#define x first
#define y second
#define pii pair<int, int>
#define p3i pair<pii, int>
#define pll pair<ll, ll>
#define p3l pair<pll, ll>
#define lseg L, (L+R)/2, N*2+1
#define rseg (L+R)/2+1, R, N*2+2
#define ub upper_bound
#define lb lower_bound
#define pq priority_queue
#define MN 1000000007
#define fox(k, x) for (int k=0; k<x; ++k)
#define fox1(k, x) for (int k=1; k<=x; ++k)
#define foxr(k, x) for (int k=x-1; k>=0; --k)
#define fox1r(k, x) for (int k=x; k>0; --k)
#define ms multiset
#define flood(x) memset(x, 0x3f3f3f3f, sizeof x)
#define drain(x) memset(x, 0, sizeof x)

int n, m, X, Y, ans;
char g[4005][4005];
bool u[4005][4005];
queue<pii> q[2];
void bfs(){
    bool k;
    q[0].push(mp(1, 1));
    for (ans=0; !q[0].empty(); ans+=k){
        k=0;
        //cout << "*";
        while(!q[0].empty()){
            X=q[0].front().x; Y=q[0].front().y; q[0].pop();
            if (u[X][Y]) continue;
            u[X][Y]=1;
            k=1;
            if (!(X+1>n || g[X+1][Y]=='.' || u[X+1][Y]))
            q[g[X+1][Y]!=g[X][Y]].push(mp(X+1, Y));
            if (!(X-1<1 || g[X-1][Y]=='.' || u[X-1][Y]))
            q[g[X-1][Y]!=g[X][Y]].push(mp(X-1, Y));
            if (!(Y+1>m || g[X][Y+1]=='.' || u[X][Y+1]))
            q[g[X][Y+1]!=g[X][Y]].push(mp(X, Y+1));
            if (!(Y-1<0 || g[X][Y-1]=='.' || u[X][Y-1]))
            q[g[X][Y-1]!=g[X][Y]].push(mp(X, Y-1));
        }
        q[0]=q[1];
        while(!q[1].empty()) q[1].pop();
    }
}
int main(){
    scanf("%i%i", &n, &m);
    fox1(l, n){
        fox1(l2, m){
            scanf(" %c", &g[l][l2]);
        }
    }
    bfs();
    cout << ans << endl;
    return 0;
}

Compilation message (stderr)

tracks.cpp: In function 'int main()':
tracks.cpp:55:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%i%i", &n, &m);
                          ^
tracks.cpp:58:36: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf(" %c", &g[l][l2]);
                                    ^

• Subtask 1: 30 / 30
• Subtask 2: 54.6875 / 70