Submission #320864

#	Time	Username	Problem	Language	Result	Execution time	Memory
320864		colazcy	Patkice (COCI20_patkice)	C++17	50 / 50	1 ms	1132 KiB

patkice

#include <cstdio>
#include <cstring>
#include <vector>
#include <queue>
using namespace std;
typedef long long ll;
const int maxn = 128,dx[] = {0,-1,1,0},dy[] = {1,0,0,-1};
const char *str = "ENSW";
struct edge{int v,d;};
vector<edge> G[maxn * maxn];
inline void addedge(int u,int v,int d){G[u].push_back(edge{v,d});}
int n,m,vis[maxn * maxn];
inline int get(int x,int y){return (x - 1) * m + y;}
struct node{
	int u;
	ll h;
	bool operator < (const node &rhs)const{
		return h > rhs.h;
	}
};
ll dis[maxn * maxn];
inline void dijkstra(int s){
	memset(dis,0x7f,sizeof(dis));
	memset(vis,0,sizeof(vis));
	dis[s] = 0;
	priority_queue<node> q;
	q.push(node{s,0});
	while(!q.empty()){
		int u = q.top().u;q.pop();
		if(vis[u])continue;
		vis[u] = 1;
		for(int i = 0;i < (int)G[u].size();i++){
			const edge &e = G[u][i];
			if(dis[u] + e.d < dis[e.v]){
				dis[e.v] = dis[u] + e.d;
				q.push(node{e.v,dis[e.v]});
			}
		}
	}
}
char mp[maxn][maxn];
int main(){
	scanf("%d %d",&n,&m);
	for(int i = 1;i <= n;i++)scanf("%s",mp[i] + 1);
	for(int i = 1;i <= n;i++)
		for(int j = 1;j <= m;j++)
			if(mp[i][j] == '<')addedge(get(i,j),get(i,j - 1),1);
			else if(mp[i][j] == '>')addedge(get(i,j),get(i,j + 1),1);
			else if(mp[i][j] == '^')addedge(get(i,j),get(i - 1,j),1);
			else if(mp[i][j] == 'v')addedge(get(i,j),get(i + 1,j),1);
	int sx,sy,tx,ty;
	for(int i = 1;i <= n;i++)
		for(int j = 1;j <= m;j++)
			if(mp[i][j] == 'o')sx = i,sy = j;
			else if(mp[i][j] == 'x')tx = i,ty = j;
	ll tmp = 0x7fffffffffffffff;char ans = 'G';
	for(int i = 0;i < 4;i++){
		int nx = sx + dx[i],ny = sy + dy[i];
		dijkstra(get(nx,ny));
		if(dis[get(tx,ty)] < tmp){
			tmp = dis[get(tx,ty)];
			ans = str[i];
		}
	}
	if(tmp != 0x7f7f7f7f7f7f7f7f)puts(":)"),putchar(ans);
	else puts(":(");
	return 0;
}

Compilation message (stderr)

patkice.cpp: In function 'int main()':
patkice.cpp:43:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   43 |  scanf("%d %d",&n,&m);
      |  ~~~~~^~~~~~~~~~~~~~~
patkice.cpp:44:32: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   44 |  for(int i = 1;i <= n;i++)scanf("%s",mp[i] + 1);
      |                           ~~~~~^~~~~~~~~~~~~~~~
patkice.cpp:13:50: warning: 'ty' may be used uninitialized in this function [-Wmaybe-uninitialized]
   13 | inline int get(int x,int y){return (x - 1) * m + y;}
      |                                                  ^
patkice.cpp:51:15: note: 'ty' was declared here
   51 |  int sx,sy,tx,ty;
      |               ^~
patkice.cpp:51:12: warning: 'tx' may be used uninitialized in this function [-Wmaybe-uninitialized]
   51 |  int sx,sy,tx,ty;
      |            ^~
patkice.cpp:58:23: warning: 'sy' may be used uninitialized in this function [-Wmaybe-uninitialized]
   58 |   int nx = sx + dx[i],ny = sy + dy[i];
      |                       ^~
patkice.cpp:58:7: warning: 'sx' may be used uninitialized in this function [-Wmaybe-uninitialized]
   58 |   int nx = sx + dx[i],ny = sy + dy[i];
      |       ^~

• Subtask 1: 30 / 30
• Subtask 2: 20 / 20