Submission #666642

#	Time	Username	Problem	Language	Result	Execution time	Memory
666642		AmirH	Robots (APIO13_robots)	C++14	30 / 100	17 ms	10076 KiB

robots

#include<iostream>
#include<algorithm>
#include<math.h>
#include<vector>
#include<bitset>
#include<queue>
#include<queue>
#include<deque>
#include<set>
#include<map>
#include<unordered_map>
#include<list>
#include<utility>
#include<stack>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair <ll, ll> pll;
typedef pair <int, int> pii;
#define cl clear
#define F  first
#define S  second
#define pb push_back
#define Sz(x) int((x).size())
#define all(x) (x).begin(), (x).end()
#define faster ios::sync_with_stdio(0), cin.tie(0), cout.tie(0)
const int MAX_N = 5e2 + 10;
const ll INF = 1e18;
const int inf = 1e9;
void free() {
    #ifndef ONLINE_JUDGE
        freopen("input.txt", "r", stdin);
        freopen("output.txt", "w", stdout);
    #endif
}
int n, w, h;
char ch[MAX_N][MAX_N];
set<int> sat[MAX_N], sot[MAX_N];
set<int> satan[MAX_N], sotan[MAX_N];
vector<int> adj[MAX_N];
int heightst[MAX_N][2];
int rast[MAX_N * MAX_N], chap[MAX_N * MAX_N], bala[MAX_N * MAX_N], paiin[MAX_N * MAX_N];
// dir : chap = 0, rast = 1, paiin = 2, bala = 3
bool check[MAX_N][MAX_N][5];
int final_ex[MAX_N][MAX_N][5];
int get(int x, int y) {
    return (x - 1) * w + y;
}
int find_ex(int x, int y, int dir) {
    if(final_ex[x][y][dir] != 0)
        return final_ex[x][y][dir];
    if(check[x][y][dir])
        return 0;
    check[x][y][dir] = 1;
    int st;
    if(dir == 0) {
        st = *(--sat[x].lower_bound(y));
        if(ch[x][st] == 'x')
            return final_ex[x][y][dir] = get(x, st + 1);
        else if(ch[x][st] == 'A')
           return final_ex[x][y][dir] = find_ex(x, st, 2);
        else
           return final_ex[x][y][dir] = find_ex(x, st, 3);
    }
    if(dir == 1) {
        st = *(sat[x].upper_bound(y));
        if(ch[x][st] == 'x')
            return final_ex[x][y][dir] = get(x, st - 1);
        else if(ch[x][st] == 'A') 
            return final_ex[x][y][dir] = find_ex(x, st, 3);
        else
           return final_ex[x][y][dir] = find_ex(x, st, 2);
    }
    if(dir == 2) {
        st = *(sot[y].upper_bound(x));
        if(ch[st][y] == 'x')
            return final_ex[x][y][dir] = get(st - 1, y);
        else if(ch[st][y] == 'A')
            return final_ex[x][y][dir] = find_ex(st, y, 1);
        else
            return final_ex[x][y][dir] = find_ex(st, y, 0);
    }
    if(dir == 3) {
        st = *(--sot[y].lower_bound(x));
        //cout << "!" << st << '\n';
        if(ch[st][y] == 'x')
            return final_ex[x][y][dir] = get(st + 1, y);
        else if(ch[st][y] == 'A')
            return final_ex[x][y][dir] = find_ex(st, y, 0);
        else
            return final_ex[x][y][dir] = find_ex(st, y, 1);
    }
}

void bfs(int st, int ft, int d) {
    int height[MAX_N];
    bool mark[MAX_N];
    for(int i = 1; i <= h * w; i++)
        height[i] = inf, mark[i] = false;
    queue<int> q;
    q.push(st);
    mark[st] = true;
    height[st] = 0;
    while(q.size()) {
        int x = q.front();
        q.pop();
        for(auto i : adj[x])
            if(!mark[i]) {
                mark[i] = true;
                q.push(i);
                height[i] = height[x] + 1;
            }
    }
    for(int i = 1; i <= h * w; i++)
        heightst[i][d] = height[i];
}
void find(int x, int y) {
    int st = get(x, y);
    rast[st] = find_ex(x, y, 1);
    chap[st] = find_ex(x, y, 0);
    bala[st] = find_ex(x, y, 3);
    paiin[st] = find_ex(x, y, 2);
    if(rast[st] != st && rast[st] != 0) {
        adj[st].pb(rast[st]);
    }
    if(chap[st] != st && chap[st] != 0) {
        adj[st].pb(chap[st]);
    }
    if(paiin[st] != st && paiin[st] != 0) {
        adj[st].pb(paiin[st]);
    }
    if(bala[st] != st && bala[st] != 0) {
        adj[st].pb(bala[st]);
    }
}
int main() {
    faster; //free();
    cin >> n >> w >> h;
    for(int i = 0; i <= h + 1; i++){
        for(int j = 0; j <= w + 1; j++) {
            if(i == 0 || i == h + 1 || j == 0 || j == w + 1)
                ch[i][j] = 'x';
            else
                cin >> ch[i][j];
            if(ch[i][j] == 'x' || ch[i][j] == 'A' || ch[i][j] == 'C') {
                sat[i].insert(j);
                sot[j].insert(i);
            }
        }
    }
    int st, ft;
    for(int i = 1; i <= h; i++) {
        for(int j = 1; j <= w; j++) {
            if(ch[i][j] == 'x')
                continue;
            find(i, j);
            if(ch[i][j] == '1')
                st = get(i, j);
            else if(ch[i][j] == '2')
                ft = get(i, j);
        }
    }
    bfs(st,ft, 0);
    bfs(ft, st, 1);
    int res = inf;
    for(int i = 1; i <= h; i++) {
        for(int j = 1; j <= w; j++) {
            if(ch[i][j] != 'x') {
                res = min(res, heightst[get(i, j)][0] + heightst[get(i, j)][1]);
            }
        }
    }
    if(res == inf)
        cout << -1;
    else
        cout << res;
}

Compilation message (stderr)

robots.cpp: In function 'void free()':
robots.cpp:32:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   32 |         freopen("input.txt", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
robots.cpp:33:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   33 |         freopen("output.txt", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
robots.cpp: In function 'int find_ex(int, int, int)':
robots.cpp:93:1: warning: control reaches end of non-void function [-Wreturn-type]
   93 | }
      | ^
robots.cpp: In function 'int main()':
robots.cpp:164:8: warning: 'ft' may be used uninitialized in this function [-Wmaybe-uninitialized]
  164 |     bfs(ft, st, 1);
      |     ~~~^~~~~~~~~~~
robots.cpp:164:8: warning: 'st' may be used uninitialized in this function [-Wmaybe-uninitialized]

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 0 / 30
• Subtask 4: 0 / 40