mirror of
https://github.com/Kiritow/OJ-Problems-Source.git
synced 2024-03-22 13:11:29 +08:00
121 lines
2.6 KiB
C++
121 lines
2.6 KiB
C++
#include <iostream>
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#include <cstdio>
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#include <memory.h>
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#include <queue>
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#include <set>
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#include <utility>
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#define MAX(a , b) ((a) > (b) ? (a) : (b))
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#define sqr(x) ((x) * (x))
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#define mp make_pair
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typedef long long ll;
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using namespace std;
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const int maxn = 12;
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const int maxm = 400000;
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const int kr = 1;
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const int prime = 999997;
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struct ddd
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{
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int x,y;
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int step;
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};
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struct node
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{
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int x,y;
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int next;
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}edge[maxm];
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int head[prime],vec[maxn][2];
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queue <ddd> Q;
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int sx,sy,tx,ty,a,b,c,d,n,idx;
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void init()
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{
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memset(head,-1,sizeof(head));
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idx = 0;
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return;
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}
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int ha(int x,int y)
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{
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return (((x << 15) ^ y) % prime + prime) % prime;
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}
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bool addedge(int key,int x,int y)
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{
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for(int i=head[key];i != -1;i=edge[i].next)
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{
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if(edge[i].x == x && edge[i].y == y) return false;
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}
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edge[idx].x = x;
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edge[idx].y = y;
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edge[idx].next = head[key];
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head[key] = idx++;
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return true;
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}
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void read()
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{
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d = 0;
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scanf("%d %d %d %d",&sx,&sy,&tx,&ty);
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scanf("%d",&n);
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for(int i=0;i<n;i++)
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{
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scanf("%d %d",&vec[i][0],&vec[i][1]);
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d = MAX(d , sqr(vec[i][0]) + sqr(vec[i][1]));
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}
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a = ty - sy;
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b = sx - tx;
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c = sy * tx - sx * ty;
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return;
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}
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bool IsValid(int x,int y)
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{
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if(sqr(x - sx) + sqr(y - sy) <= sqr(kr) * d) return true;
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if(sqr(x - tx) + sqr(y - ty) <= sqr(kr) * d) return true;
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if((tx - sx) * (x - sx) + (ty - sy) * (y - sy) < 0) return false;
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if((sx - tx) * (x - tx) + (sy - ty) * (y - ty) < 0) return false;
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if(sqr(ll(a) * x + b * y + c) <= ll(d) * (sqr(a) + sqr(b))) return true;
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return false;
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}
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void bfs()
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{
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while(!Q.empty()) Q.pop();
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ddd cur,tmp;
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tmp.x = sx;
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tmp.y = sy;
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tmp.step = 0;
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Q.push(tmp);
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addedge(ha(sx , sy) , sx , sy);
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while(!Q.empty())
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{
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cur = Q.front();
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Q.pop();
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if(cur.x == tx && cur.y == ty)
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{
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printf("%d\n",cur.step);
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return;
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}
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for(int i=0;i<n;i++)
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{
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int xx = cur.x + vec[i][0];
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int yy = cur.y + vec[i][1];
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if(IsValid(xx , yy) && addedge(ha(xx , yy) , xx , yy))
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{
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tmp.x = xx;
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tmp.y = yy;
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tmp.step = cur.step + 1;
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Q.push(tmp);
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}
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}
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}
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puts("IMPOSSIBLE");
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return;
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}
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int main()
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{
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int cas;
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scanf("%d",&cas);
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while(cas--)
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{
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init();
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read();
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bfs();
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}
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return 0;
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}
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