This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define f first
#define s second
#define ii pair<int,int>
#define qit pair<ii, ll>
vector<vector<int> > wallsr, wallsc; //wallsr means c of walls, given r, and vice versa.
ii get_walls_with_c(int r, int c) {
// stuff with wallsc
int small=0, large=wallsc[c].size()-1, mid;
while (large-small > 1) {
mid = (small+large)/2;
if (wallsc[c][mid] > r) {
large = mid; // so, r < wallsc[large] , always. (since last is always outside)
} else {
small = mid; // so, wallsc[small] <= r, always. (since first is always outside)
}
}
if (wallsc[c][small] == r) small--;
return ii(wallsc[c][small], wallsc[c][large]);
}
ii get_walls_with_r(int r, int c) {
// stuff with wallsr
int small=0, large=wallsr[r].size()-1, mid;
while (large-small > 1) {
mid = (small+large)/2;
if (wallsr[r][mid] > c) {
large = mid; // so, r < wallsc[large] , always. (since last is always outside)
} else {
small = mid; // so, wallsc[small] <= r, always. (since first is always outside)
}
}
if (wallsr[r][small] == c) small--;
return ii(wallsr[r][small], wallsr[r][large]);
}
/*
class qit {
public:
ii f;
ll s;
qit(ii vals, ll dist) {
f = vals;
s = dist;
}
bool operator<(qit b) {
return s < b.s;
}
bool operator>(qit b) {
return s > b.s;
}
const bool operator<(qit b) {
return s < b.s;
}
const bool operator>(qit b) {
return s > b.s;
}
};
*/
class cmp {
public:
int operator()(qit a, qit b) {
return greater<ll>()(a.s, b.s);
}
};
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int r, c;
cin >> r >> c;
int maze[r+3][c+3];
for (int i=0; i<=r+1; i++) {
wallsr.push_back(vector<int>());
wallsr[i].push_back(0);
}
for (int i=0; i<=c+1; i++) {
wallsc.push_back(vector<int>());
wallsc[i].push_back(0);
}
char temp;
ii start;
for (int i=1; i<=r; i++) {
for (int j=1; j<=c; j++) {
cin >> temp;
if (temp == '#') {
maze[i][j] = -1;
wallsr[i].push_back(j); // this will be in ascending order
wallsc[j].push_back(i); // but not definitely this (?)
}
else if (temp == 'C') maze[i][j] = 1;
else {
maze[i][j] = 0;
if (temp == 'S') {
start = ii(i, j);
}
}
}
}
for (int i=0; i<=r+1; i++) {
wallsr[i].push_back(c+1);
}
for (int i=0; i<=c+1; i++) {
wallsc[i].push_back(r+1);
}
// just in case
for (int col=1; col<=c; col++) {
sort(wallsc[col].begin(), wallsc[col].end());
}
bool visited[r+2][c+2];
for (int i=1; i<=r; i++) {
for (int j=1; j<=c; j++) {
visited[i][j] = false;
}
}
// outline borders
for (int i=0; i<=r+1; i++) {
visited[i][0] = true;
visited[i][c+1] = true;
}
for (int j=0; j<c+1; j++) {
visited[0][j] = true;
visited[r+1][j] = true;
}
priority_queue<qit, vector<qit>, cmp> bfs;
bfs.push(qit(start,0));
qit curr = qit(start,0); // temp value
ii cpos;
ii rwalls, cwalls;
int closest;
while (!bfs.empty()) {
curr = bfs.top(); bfs.pop();
cpos = curr.f;
//cout << "CHECKING (" << cpos.f << ',' << cpos.s << "): " << curr.s << endl;
//if (cpos.f<0 || cpos.f>r || cpos.s<0 || cpos.s>c) continue; // this means it go out of map bounds, so ignore.
if (visited[cpos.f][cpos.s]) continue;
visited[cpos.f][cpos.s] = true;
if (maze[cpos.f][cpos.s] == 1) {
cout << curr.s << '\n';
return 0;
} else if (maze[cpos.f][cpos.s] == -1) continue; // means that just ignore yea.
// try moving in all four directions normally
bfs.push(qit(ii(cpos.f-1, cpos.s), curr.s+1));
bfs.push(qit(ii(cpos.f+1, cpos.s), curr.s+1));
bfs.push(qit(ii(cpos.f, cpos.s-1), curr.s+1));
bfs.push(qit(ii(cpos.f, cpos.s+1), curr.s+1));
// try going to each wall using portal
rwalls = get_walls_with_c(cpos.f, cpos.s);
cwalls = get_walls_with_r(cpos.f, cpos.s);
//cout << "R: " << cpos.f << ", C: " << cpos.s << endl;
//cout << "RWALLS: " << rwalls.f << ' ' << rwalls.s << endl;
//cout << "CWALLS: " << cwalls.f << ' ' << cwalls.s << endl;
// these shldn't need abs, but jic.
closest = min( min( abs(cpos.f-rwalls.f) , abs(rwalls.s-cpos.f) ) ,
min( abs(cpos.s-cwalls.f) , abs(cwalls.s-cpos.s) ) );
//cout << "CLOSEST: " << closest << endl << endl;
// try portal gun in all 4 directions
bfs.push(qit(ii(rwalls.f+1, cpos.s), curr.s+closest));
bfs.push(qit(ii(rwalls.s-1, cpos.s), curr.s+closest));
bfs.push(qit(ii(cpos.f, cwalls.f+1), curr.s+closest));
bfs.push(qit(ii(cpos.f, cwalls.s-1), curr.s+closest));
}
// should never happen...
cout << -1 << '\n';
return 0;
return 0;
}
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