Submission #1316473

#	Time	Username	Problem	Language	Result	Execution time	Memory
1316473		dex111222333444555	Mecho (IOI09_mecho)	C++20	100 / 100	183 ms	6408 KiB

mecho

#include <bits/stdc++.h>
#define all(v) begin(v), end(v)
#define ii pair<int, int>
#define fi first
#define se second

using namespace std;

const int MAXN = 805, MAXS = 1006, infINT = 1e9 + 234;

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

template<class X, class Y> bool minimize(X &x, const Y &y){return x > y ? x = y, 1: 0;}

int numSize, maxRange, bee[MAXN][MAXN], mecho[MAXN][MAXN];
char board[MAXN][MAXN];

void input(){
    cin >> numSize >> maxRange;
    for(int row = 1; row <= numSize; row++)
    for(int col = 1; col <= numSize; col++)
        cin >> board[row][col];
}

bool isValid(int row, int col){
    return 1 <= min(row, col) && max(row, col) <= numSize;
}

void bfsBee(){
    #define PUSH(row, col, d) if (minimize(bee[row][col], d)) q.emplace(row, col)
    memset(bee, 0x3f, sizeof bee);

    queue<ii> q;
    for(int row = 1; row <= numSize; row++)
    for(int col = 1; col <= numSize; col++) if (board[row][col] == 'H')
        PUSH(row, col, 0);

    while(q.size()){
        int row = q.front().fi, col = q.front().se;
        q.pop();
        for(int k = 0; k < 4; k++){
            int nrow = row + dx[k], ncol = col + dy[k];
            if (isValid(nrow, ncol) && (board[nrow][ncol] == 'G' || board[nrow][ncol] == 'M')){
                PUSH(nrow, ncol, bee[row][col] + 1);
            }
        }
    }
}

bool bfsMecho(const int &mid){
    #define PUSH(row, col, d) if (minimize(mecho[row][col], d)) q.emplace(row, col)
    memset(mecho, 0x3f, sizeof mecho);

    queue<ii> q;
    for(int row = 1; row <= numSize; row++)
    for(int col = 1; col <= numSize; col++) if (board[row][col] == 'M' && bee[row][col] > mid)
        PUSH(row, col, 0);

    while(q.size()){
        int row = q.front().fi, col = q.front().se;
        q.pop();
        for(int k = 0; k < 4; k++){
            int nrow = row + dx[k], ncol = col + dy[k];
            if (isValid(nrow, ncol) && (board[nrow][ncol] == 'G' || board[nrow][ncol] == 'M' || board[nrow][ncol] == 'D')){
                if ((mecho[row][col] + 1) / maxRange < bee[nrow][ncol] - mid)
                    PUSH(nrow, ncol, mecho[row][col] + 1);
            }
        }
    }

    for(int row = 1; row <= numSize; row++)
    for(int col = 1; col <= numSize; col++) if (board[row][col] == 'D' && mecho[row][col] < infINT)
        return 1;

    return 0;
}

bool check(const int &mid){
    return bfsMecho(mid);
}

void solve(){
    bfsBee();
    int l = 0, r = numSize * numSize, m, res = -1;
    while(l <= r){
        m = (l + r) >> 1;
        if (check(m)) res = m, l = m + 1;
        else r = m - 1;
    }
    cout << res << '\n';
}

int main(){
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    #define task "test"
    if (fopen(task".inp", "r")){
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }
    input();
    solve();
}

Compilation message (stderr)

mecho.cpp:52: warning: "PUSH" redefined
   52 |     #define PUSH(row, col, d) if (minimize(mecho[row][col], d)) q.emplace(row, col)
      | 
mecho.cpp:31: note: this is the location of the previous definition
   31 |     #define PUSH(row, col, d) if (minimize(bee[row][col], d)) q.emplace(row, col)
      | 
mecho.cpp: In function 'int main()':
mecho.cpp:98:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   98 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
mecho.cpp:99:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   99 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 100 / 100