Source

Problem Id:3029  User Id:qiqilrq
Memory:188K  Time:515MS
Language:G++  Result:Wrong Answer

    * Source

      #include <stdio.h>
      #include <math.h>
      #include <algorithm>
      using namespace std;

      typedef struct {
          int id;
          double x, y, v, a;
      }guest;

      guest G[10];
      bool cmp(guest g1,guest g2){
          return g1.id<g2.id;
      }
      double gv;
      int n;
      double gettime()
      {
          double gdx=0, gdy=0;    //guide position
          double curt=0, rett=0;
          for(int i=0;i<n;i++){
              double vx=G[i].v*cos(G[i].a), vy=G[i].v*sin(G[i].a);
              double x0=G[i].x+curt*vx-gdx, y0=G[i].y+curt*vy-gdy;
              double aa=gv*gv-G[i].v*G[i].v,  bb=x0*vx+y0*vy, cc=x0*x0+y0*y0;
              double ct=(bb+sqrt(bb*bb+aa*cc))/aa;     //catch time
              curt+=ct;           //current time
              gdx = G[i].x+vx*ct;
              gdy = G[i].y+vy*ct; //update guide position
              double dist=sqrt(gdx*gdx+gdy*gdy);
              double thistime=dist/G[i].v+curt;
              if(thistime>rett)
                  rett=thistime;
          }
          return rett;
      }

      int main()
      {
          scanf("%d",&n);
          while(n>0){
              int i,j=1;
              scanf("%lf",&gv);
              memset(G,0,10*sizeof(G[0]));
              for(i=0;i<n;i++) {
                  scanf("%lf%lf%lf%lf",&G[i].x,&G[i].y,&G[i].v,&G[i].a);
                  G[i].id=i;
              }
              double mt=gettime();
              while(next_permutation(G,G+n, cmp)){
                  double t=gettime();
                  //cout<<j++<<": "<<t<<endl;
                  if(t<mt) 
                      mt=t;
              }
              printf("%.0f\n",mt);
              scanf("%d",&n);
          }
      }
      /*
      1
      50.0
      123.0 175.0 25.0 1.96
      3
      100.0
      40 25 20 5.95
      -185 195 6 2.35
      30 -80 23 2.76
      0
      */

• 果然是代码写得有问题，update guide position那里写错了 (0) qiqilrq 2007-08-07 00:13:07