Submission #19618

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Source Code Expand

#include <iostream>
#include <sstream>
#include <fstream>
#include <string>
#include <vector>
#include <list>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <deque>
#include <complex>
#include <algorithm>
#include <cstdio>
#include <cmath>
#include <cstring>

#define REP(i,x) for(int i=0 ; i<(int)(x) ; i++)
#define ALL(x) (x).begin(),(x).end()
#define LL long long

using namespace std;

class C{
	struct Node{
		int next;
		int sec;
		double cost;
		Node(int n,int s):next(n),sec(s){}
		Node(int n,int s,double c):next(n),sec(s),cost(c){}
	};
	int N,M;
	int sy,sx,gy,gx;
	vector<string> field;
	vector<double> pre;
	bool isValid(int y,int x){
		return y>=0 && y<N && x>=0 && x<M;
	}
public:
	bool init(){
		if(scanf("%d%d",&N,&M)==EOF)return false;
		field.resize(N);
		REP(i,N){
			char buf[1024];
			scanf("%s",buf);
			field[i] = string(buf);
		}
		return true;
	}
	int check(double mid){
		vector<vector<double> > used(N,vector<double>(M,-2));
		queue<Node> que;que.push(Node(sy*M+sx,0,100));
		while(!que.empty()){
			Node n = que.front();que.pop();
			int cy = n.next/M;
			int cx = n.next%M;
			if(cy==gy && cx==gx)return 1;
			const int DY[] = {-1,0,1,0};
			const int DX[] = {0,1,0,-1};
			REP(i,4){
				int ny = cy+DY[i];
				int nx = cx+DX[i];
				
				if(!isValid(ny,nx) || field[ny][nx]=='#')continue;
				double cost = field[ny][nx]-'0';
				cost *= pre[n.sec+1];
				if(field[ny][nx]=='g')cost = 100;
				cost = min(n.cost,cost);
				if(cost>mid && used[ny][nx]<cost){
					used[ny][nx] = cost;
					que.push(Node(ny*M+nx,n.sec+1,cost));
				}
			}
		}
		return 0;
	}
	void solve(){
		REP(y,N)REP(x,M){
			if(field[y][x]=='s'){
				sy = y;
				sx = x;
			}
			if(field[y][x]=='g'){
				gy = y;
				gx = x;
			}
		}
		pre.assign(4*N*M,1);
		REP(i,4*N*M-1)pre[i+1] = pre[i]*0.99;
		vector<vector<double> > used(N,vector<double>(M,-2));
		vector<vector<int> > inQue(N,vector<int>(M,0));
		queue<Node> que;que.push(Node(sy*M+sx,0));
		inQue[sy][sx] = 1;
		used[sy][sx] = 100;
		while(!que.empty()){
			Node n = que.front();que.pop();
			int cy = n.next/M;
			int cx = n.next%M;
			//cout << cy << "," << cx << " " << used[cy][cx] << endl;
			inQue[cy][cx] = 0;
			const int DY[] = {-1,0,1,0};
			const int DX[] = {0,1,0,-1};
			REP(i,4){
				int ny = cy+DY[i];
				int nx = cx+DX[i];
				
				if(!isValid(ny,nx) || field[ny][nx]=='#')continue;
				double cost = field[ny][nx]-'0';
				cost *= pre[n.sec+1];
				if(field[ny][nx]=='g')cost = 100;
				cost = min(used[cy][cx],cost);
				if(used[ny][nx]<cost){
					used[ny][nx] = cost;
					if(!inQue[ny][nx]){
						inQue[ny][nx] = 1;
						que.push(Node(ny*M+nx,n.sec+1));
					}
				}
			}
		}
		double lb = 0,ub = 10;
		REP(i,50){
			double mid = (lb+ub)/2;
			if(check(mid))lb = mid;
			else ub = mid;
		}
		if(lb<1e-9)printf("-1\n");
		else printf("%.9f\n",lb);

		//if(used[gy][gx]<-1)printf("-1\n");
		//else printf("%.9f\n",(double)used[gy][gx]);
	}
};

int main(){
	C solver;
	while(solver.init()){
		solver.solve();
	}
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In member function ‘bool C::init()’:
./Main.cpp:45:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]

Judge Result