Submission #1049036

#	Time	Username	Problem	Language	Result	Execution time	Memory
1049036		adiyer	Robots (APIO13_robots)	C++17	100 / 100	221 ms	138436 KiB

robots

#include<algorithm>
#include<vector>
#include<iostream>
#include<string>
#include<cstring>
#include<cstdio>
#include<queue>

#define fr first
#define sc second
#define mp make_pair
#define pb push_back
#define REP(i,m) for(int i=0;i<(int)m;++i)
#define REPN(i,m,in) for(int i=in;i<(int)m;++i)
#define ALL(t) (t).begin(),(t).end()
#define dump(x) cerr<<#x<<" = "<<x<<endl
#define prl cerr<<"LINE "<<__LINE__<<" is called"<<endl

using namespace std;
template<class T> void debug(T a,T b){ for(;a!=b;++a) cerr<<*a<<' '; cerr<<endl ; }

typedef pair<int,int> pi;
typedef long long int lint;
const int INF=510000000;

char buf[505][505];
int dp[50][505][505];

pi g[505][505][4];

bool vis[505][505][4];

int n,w,h;
int dx[]={0,1,0,-1},dy[]={1,0,-1,0};
pi rec(int y,int x,int d){
    pi& res=g[y][x][d];
	if(res.fr!=-1) return res;
	if(vis[y][x][d]) return res=mp(-2,-2);
	vis[y][x][d]=1;

	if(buf[y][x]=='A') d=(d+1)%4;
	if(buf[y][x]=='C') d=(d+3)%4;

	int px=x+dx[d],py=y+dy[d];
	if(px<0 || py<0 || px>=w || py>=h || buf[py][px]=='x'){
		return res=mp(y,x);
	}
	return res=rec(py,px,d);
}

pi pos[10];
int hsh[10][10];

void prep(int sy,int sx,int id){
	queue<pi> q;
	dp[hsh[id][id+1]][sy][sx]=0;
	q.push(mp(sy,sx));

	while(!q.empty()){
		pi cur=q.front();q.pop();

		REP(d,4){
			pi to=g[cur.fr][cur.sc][d];

			if(to.fr==-2) continue;

			if(dp[hsh[id][id+1]][to.fr][to.sc]!=-1) continue;

			dp[hsh[id][id+1]][to.fr][to.sc]=dp[hsh[id][id+1]][cur.fr][cur.sc]+1;

			q.push(to);
		}
	}

	REP(i,h) REP(j,w) if(dp[hsh[id][id+1]][i][j]==-1) dp[hsh[id][id+1]][i][j]=INF;
}

vector<pi> posByCost[500*501*10];
vector<int> used;

int main(){
	int cntt=0;
	REP(i,9) REPN(j,10,i+1) hsh[i][j]=cntt++;
	scanf("%d%d%d",&n,&w,&h);

	REP(i,h) scanf("%s",buf[i]);
	REP(i,h) REP(j,w){
		if(buf[i][j]>='1' && buf[i][j]<='9'){
			pos[buf[i][j]-'1']=mp(i,j);
		}
	}
	memset(g,-1,sizeof(g));
	REP(i,h) REP(j,w) REP(d,4) rec(i,j,d);

	memset(dp,-1,sizeof(dp));
	REP(i,n){
		prep(pos[i].fr,pos[i].sc,i);
	}


	queue<pi> q;

	for(int len=2;len<=n;++len) REP(i,n-len+1){
		int j=i+len;

		pair<int,pi> mini;mini.fr=INF;
		
		REP(y,h) REP(x,w){
			dp[hsh[i][j]][y][x]=INF;
			REP(k,len-1){
				int div=i+k+1;
				dp[hsh[i][j]][y][x]=min(dp[hsh[i][j]][y][x],dp[hsh[i][div]][y][x]+dp[hsh[div][j]][y][x]);
			}
			if(dp[hsh[i][j]][y][x]!=INF){
				used.pb(dp[hsh[i][j]][y][x]);
				posByCost[dp[hsh[i][j]][y][x]].pb(mp(y,x));
				mini=min(mini,mp(dp[hsh[i][j]][y][x],mp(y,x)));
			}
		}
		if(mini.fr==INF) continue;
		REP(k,posByCost[mini.fr].size()) q.push(posByCost[mini.fr][k]);
		posByCost[mini.fr].clear();
	

		while(!q.empty()){

			pi p=q.front();q.pop();
			int c=dp[hsh[i][j]][p.fr][p.sc];
			if(!posByCost[c+1].empty()){
				REP(k,posByCost[c+1].size()){
					pi p2=posByCost[c+1][k];
					if(dp[hsh[i][j]][p2.fr][p2.sc]<c+1) continue;
					q.push(p2);
				}
				posByCost[c+1].clear();
			}
			REP(d,4){
				pi nxt=g[p.fr][p.sc][d];
				if(nxt.fr==-2 || dp[hsh[i][j]][nxt.fr][nxt.sc]<=c+1) continue;
				dp[hsh[i][j]][nxt.fr][nxt.sc]=c+1;
				q.push(nxt);
			}

		}
		REP(k,used.size()) posByCost[used[k]].clear();
		used.clear();
	
		
	}

	int res=INF;

	REP(i,h) REP(j,w) res=min(res,dp[hsh[0][n]][i][j]);

	if(res==INF) res=-1;

	printf("%d\n",res);



	return 0;
}

Compilation message (stderr)

robots.cpp: In function 'int main()':
robots.cpp:84:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   84 |  scanf("%d%d%d",&n,&w,&h);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~
robots.cpp:86:16: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   86 |  REP(i,h) scanf("%s",buf[i]);
      |           ~~~~~^~~~~~~~~~~~~

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