제출 #1097089

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1097089		InvMOD	Mecho (IOI09_mecho)	C++14	84 / 100	137 ms	14356 KiB

mecho

#include <bits/stdc++.h>
using namespace std;

#define fi first
#define se second
#define gcd __gcd
#define sz(v) (int) v.size()
#define pb push_back
#define pi pair<int,int>
#define all(v) (v).begin(), (v).end()
#define compact(v) (v).erase(unique(all(v)), (v).end())
#define FOR(i, a, b) for(int i = (a); i <= (b); i++)
#define int long long

using ll = long long;
using ld = long double;
using ull = unsigned long long;

template<typename T> bool ckmx(T& a, const T& b){if(a < b) return a = b, true; return false;}
template<typename T> bool ckmn(T& a, const T& b){if(a > b) return a = b, true; return false;}

const int N = 1e3+5;
const ll MOD = 1e9+7;
const ll INF = 1e18;

const int dx[4] = {1, -1, 0, 0};
const int dy[4] = {0, 0, 1, -1};

int n, s, d[N][N], vis[N][N];
char a[N][N];

bool init(int x, int y){
    return (x >= 1 && x <= n) && (y >= 1 && y <= n) && a[x][y] != 'T';
}

bool good(int time){
    pi st, ed;
    FOR(i, 1, n){
        FOR(j, 1, n){
            if(a[i][j] == 'M'){
                st = make_pair(i,j);
                vis[i][j] = 0;
            }
            else{
                if(a[i][j] == 'D'){
                    ed = make_pair(i, j);
                }
                vis[i][j] = 1e9;
            }
        }
    }

    if(time > d[st.fi][st.se]) return false;

    queue<pair<int,int>> q;
    q.push(st);

    while(sz(q)){
        pi e = q.front(); q.pop();

        int x = e.fi, y = e.se;
        for(int i = 0; i < 4; i++){
            int xx = x + dx[i];
            int yy = y + dy[i];
            if(init(xx, yy) && vis[xx][yy] == 1e9 && a[xx][yy] != 'H'){
                int n_dist = (vis[x][y] + 1) / s;
                if(n_dist < d[xx][yy] - time){
                    vis[xx][yy] = vis[x][y] + 1;
                    q.push(make_pair(xx, yy));
                }
            }
        }
    }

    return vis[ed.fi][ed.se] != 1e9;
}

void solve()
{
    cin >> n >> s;
    FOR(i, 1, n){
        FOR(j, 1, n){
            cin >> a[i][j];
        }
    }

    queue<pair<int,int>> q;

    FOR(i, 1, n){
        FOR(j, 1, n){
            if(a[i][j] == 'H'){
                q.push(make_pair(i,j));
            }
            else d[i][j] = 1e9;
        }
    }

    while(sz(q)){
        pi e = q.front(); q.pop();

        int x = e.fi, y = e.se;
        for(int i = 0; i < 4; i++){
            int xx = x + dx[i];
            int yy = y + dy[i];
            if(init(xx, yy) && d[xx][yy] == 1e9 && a[xx][yy] != 'D'){
                d[xx][yy] = d[x][y] + 1;
                q.push(make_pair(xx, yy));
            }
        }
    }

    int l = -1, r = 1e9;
    while(l+1 < r){
        int m = l+r>>1;
        if(good(m)){
            l = m;
        }
        else r = m;
    }
    cout << l <<"\n";
}

signed main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    #define name "InvMOD"
    if(fopen(name".INP", "r")){
        freopen(name".INP","r",stdin);
        freopen(name".OUT","w",stdout);
    }

    int t = 1; //cin >> t;
    while(t--) solve();
    return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

mecho.cpp: In function 'void solve()':
mecho.cpp:114:18: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  114 |         int m = l+r>>1;
      |                 ~^~
mecho.cpp: In function 'int main()':
mecho.cpp:131:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  131 |         freopen(name".INP","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
mecho.cpp:132:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  132 |         freopen(name".OUT","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 84 / 100