Submission #40408

#	Time	Username	Problem	Language	Result	Execution time	Memory
40408		mohammad_kilani	Robots (APIO13_robots)	C++14	100 / 100	731 ms	65792 KiB

robots

#include <bits/stdc++.h>
using namespace std;
#define mod 1000000007
#define oo 1000000000
const double PI = acos(-1);
const int N = 501 , MAX_COST = 500 * 75 * 9 + 1;
char grid[N][N];
int n , m , sr , sc, cnt = 0 , idx[10][10] , num , vis[N][N] , vi = 1 , row , col , nr ,nc , cost , best[50][N][N];
int dr[4] = {1,0,-1,0};
int dc[4] = {0,1,0,-1};
pair<int,int> nxt[N][N][4]; 
vector< vector< pair<int,int> > > tmp2;
vector< pair<int,pair<int,int> > > tmp;
deque < pair<int, pair<int,int> > > q;

inline void BFS(int low,int high){
	vi++;
	tmp.clear();
	tmp2.clear();
	tmp2.resize(MAX_COST);
	for(int i=0;i<n;i++){
		for(int j=0;j<m;j++){
			if(best[idx[low][high]][i][j] == oo) continue;
			tmp2[best[idx[low][high]][i][j]].push_back(make_pair(i,j));
		}
	}
	for(int i=0;i<MAX_COST;i++)
		for(int j=0;j<tmp2[i].size();j++){
			tmp.push_back(make_pair(i,tmp2[i][j]));
		}
	for(int i=0;i<tmp.size();i++){
		q.push_back(tmp[i]);
		while(!q.empty()){
			cost = q.back().first;
			row = q.back().second.first;
			col = q.back().second.second;
			q.pop_back();
			if(vis[row][col] == vi) continue;
			vis[row][col] = vi;
			best[idx[low][high]][row][col] = cost;
			while(i + 1 < tmp.size() && tmp[i + 1].first == cost){
				i++;
				if(vis[tmp[i].second.first][tmp[i].second.second] == vi) continue;
				q.push_back(tmp[i]);
			}
			for(int i=0;i<4;i++){
				nr = nxt[row][col][i].first;
				nc = nxt[row][col][i].second;
				if(nr == -1 || vis[nr][nc] == vi) continue;
				q.push_front(make_pair(cost + 1 , make_pair(nr,nc)));
			}
		}
	}
}
 
inline void make(int r,int c,int k){
	sr = r;
	sc = c;
	while(r >= 0 && r < n && c >= 0 && c < m && grid[r][c] != 'x'){
		if(grid[r][c] == 'A') k--; else if(grid[r][c] == 'C') k++;
		if(k == -1) k = 3;
		if(k == 4) k = 0;
		nxt[r][c][k] = make_pair(sr,sc);
		r = r + dr[k];
		c = c + dc[k];
	}
}
 
int main(){
	for(int i=1;i<10;i++){
		for(int j=i;j<10;j++){
			idx[i][j] = cnt++;
		}
	}
	scanf("%d%d%d",&num,&m,&n);
	for(int i=0;i<cnt;i++){
		for(int j=0;j<n;j++){
			for(int k=0;k<m;k++){
				best[i][j][k] = oo;
			}
		}
	}
	for(int i=0;i<n;i++)
		scanf("%s",grid[i]);
	for(int i=0;i<n;i++){
		for(int j=0;j<m;j++){
			if(grid[i][j] >= '1' && grid[i][j] <= '9'){
				best[idx[grid[i][j]-'0'][grid[i][j]-'0']][i][j] = 0;
			}
			for(int k=0;k<4;k++)
				nxt[i][j][k] = make_pair(-1,-1);
		}
	}
	for(int i=0;i<n;i++){
		for(int j=0;j<m;j++){
			if(grid[i][j] == 'x') continue;
			sr = i;
			sc = j;
			for(int k=0;k<4;k++){
				int nr = i + dr[k];
				int nc = j + dc[k];
				if(nr == -1 || nr == n || nc == -1 || nc == m || grid[nr][nc] == 'x'){
					make(i,j,(k + 2) % 4);
				}
			}
		}
	}
	for(int i=0;i<num;i++){
		for(int j=1;j+i<=num;j++){
			for(int row=0;row<n;row++){
				for(int col=0;col<m;col++){
					for(int k=j;k<j+i;k++){
						best[idx[j][i+j]][row][col] = min(best[idx[j][i+j]][row][col],best[idx[j][k]][row][col] + best[idx[k+1][i+j]][row][col]);
					}
				}
			}
			BFS(j,j+i);
		}
	}
	int ans = oo;
	for(int i=0;i<n;i++){
		for(int j=0;j<m;j++){
			ans = min(ans,best[idx[1][num]][i][j]);
		}
	}
	if(ans == oo) ans = -1;
	cout << ans << endl;
 	return 0;
}

Compilation message (stderr)

robots.cpp: In function 'void BFS(int, int)':
robots.cpp:28:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int j=0;j<tmp2[i].size();j++){
                ^
robots.cpp:31:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<tmp.size();i++){
               ^
robots.cpp:41:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    while(i + 1 < tmp.size() && tmp[i + 1].first == cost){
                ^
robots.cpp: In function 'int main()':
robots.cpp:75:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d%d",&num,&m,&n);
                            ^
robots.cpp:84:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%s",grid[i]);
                      ^

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