远离原点
http://47.96.116.66/problem.php?cid=1177&pid=2
http://47.96.116.66/problem.php?cid=1180&pid=2
題解：BFS
/* *@Author: STZG *@Language: C++ */ #include <bits/stdc++.h> #include<iostream> #include<algorithm> #include<cstdlib> #include<cstring> #include<cstdio> #include<string> #include<vector> #include<bitset> #include<queue> #include<deque> #include<stack> #include<cmath> #include<list> #include<map> #include<set> //#define DEBUG #define RI register int using namespace std; typedef long long ll; //typedef __int128 lll; const int N=2000+10; const int M=100000+10; const int MOD=1e9+7; const double PI = acos(-1.0); const double EXP = 1E-8; const int INF = 0x3f3f3f3f; int t,n,m,k,q; int ans,cnt,flag,temp,sum; int a[N],b[N]; bool vis[N][N]; char str; struct node{int x,y,time; }s,f,tmp; int dir[4][2]={1,0,0,1,-1,0,0,-1}; int main() { #ifdef DEBUGfreopen("input.in", "r", stdin);//freopen("output.out", "w", stdout); #endif//ios::sync_with_stdio(false);//cin.tie(0);//cout.tie(0);//scanf("%d",&t);//while(t--){scanf("%d%d",&n,&k);for(int i=1;i<=n;i++){scanf("%d",&a[i]);}for(int i=1;i<=n;i++){scanf("%d",&b[i]);vis[a[i]+1000][b[i]+1000]=1;} // for(i=990;i<=1010;i++){ // for(j=990;j<=1010;j++){ // printf("%d%c",vis[i][j]," \n"[1010==j]); // } // }queue<node>q;s.x=1000;s.y=1000;s.time=0;q.push(s);vis[1000][1000]=1;ans=1000;while(!q.empty()){f=q.front();q.pop();for(int i=0;i<4;i++){tmp.x=f.x+dir[i][0];tmp.y=f.y+dir[i][1];tmp.time=f.time+1;if(tmp.x<0||tmp.x>2000||tmp.y<0||tmp.y>2000)continue;if(vis[tmp.x][tmp.y])continue;if(tmp.time>k)continue;ans=max(tmp.x,ans);//if(t++<20)//cout<<tmp.x-1000<<" "<<tmp.y-1000<<" "<<abs(1000-tmp.x)+abs(1000-tmp.y)<<endl;vis[tmp.x][tmp.y]=1;q.push(tmp);}}cout<<ans-1000<<endl;//}#ifdef DEBUGprintf("Time cost : %lf s\n",(double)clock()/CLOCKS_PER_SEC); #endif//cout << "Hello world!" << endl;return 0; }?
總結(jié)
