【算法学习笔记】88.显式DFS SJTU OJ 2202. 梅西的过人

#include <iostream>
#include <stack>
#include <cstdio>
#include <cstring>
using namespace std;

int k,n,m;
bool map[1000+5][1000+5];
bool vis[1000+5][1000+5];
int dx[4] = {0,0,-1,+1};
int dy[4] = {+1,-1,0,0};
void init(){
cin>>n>>m;
for (int i = 1; i <= n; ++i){
for (int j = 1; j <= m; ++j){
int t;
scanf("%d",&t);
map[i][j] = t;
}
}
memset(vis,0,sizeof(vis));
}

struct Point
{
int x;
int y;
int done;
Point(int a,int b){
x = a;
y = b;
done = 0;
}
};

bool build(){
stack<Point> s;
Point start(1,1);
s.push(start);
while(!s.empty()){
Point cur = s.top();
s.pop();
vis[cur.x][cur.y] = true;
for (int i = 0; i < 4; ++i)
{
int new_x = cur.x + dx[i];
int new_y = cur.y + dy[i];
if(new_x>=1 and new_x<=n and new_y>=1 and new_y<=m){
if(!vis[new_x][new_y]){
vis[new_x][new_y] = true;
if(map[new_x][new_y]==false or cur.done == 0){
Point next(new_x,new_y);
next.done = cur.done+map[new_x][new_y];
if(next.done <= 1){
//cout<<next.x<<","<<next.y<<endl;
s.push(next);
if(new_x==n and new_y==m)
return true;
}
}
}
}
}
}
return false;
}

int main(int argc, char const *argv[])
{
cin>>k;
for (int i = 0; i < k; ++i)
{
init();
cout<<build()<<endl;
}
return 0;
}

/*
1
3 4
0 1 0 0
1 1 1 1
0 0 1 0

*/