URAL 1019-Line Painting

Just like a previous question, it is always a problem of interval dyeing. I still use my old method to implement interval discretization + binary interval endpoint + interval processing, and the time is quite short.

 

 

 
 

The problem is that the leftmost end is 0, the rightmost end is 1e9, and the interval is an open interval.

#include <stdio.h>   #include <string.h>   #include <math.h>   #include <algorithm>   using namespace std;  typedef struct  {      int l;      int r;      bool color;  }seg;  seg a[5005];  int t[10005];  int d[10005],ct;  int f[10005];    int find(int x,int n)  {      int l=0,r=n-1,mid=(l+r)/2;      while(l<r)      {          if(x>d[mid])l=mid+1;          else r=mid;          mid=(l+r)/2;      }      return mid;  }    int main()  {      int n;          scanf("%d",&n);          for(int i=0;i<n;i++)          {              char e;              scanf("%d %d %c",&t[2*i],&t[2*i+1],&e);              a[i].l=t[2*i];              a[i].r=t[2*i+1];              a[i].color=(e=='w')?0:1;          }          t[2*n]=0;t[2*n+1]=1e9;          sort(t,t+2*n+2);          ct=0;          d[ct++]=t[0];          for(int i=1;i<2*n+2;i++)              if(t[i]!=t[i-1])              d[ct++]=t[i];          memset(f,0,sizeof(f));          for(int i=0;i<n;i++)          {                 int L=find(a[i].l,ct);                 int R=find(a[i].r,ct);                 for(int j=L;j<R;j++)                  f[j]=a[i].color;          }          int left=0;          int max=0,a1,a2;          for(int i=0;i<ct;i++)          {              if(f[i]==1||d[i]==1e9)              {                  if(left==d[i]){left=d[i+1];continue;}                  else {                          if(d[i]-left>max){                                  max=d[i]-left;                                  a1=left;                                  a2=d[i];                          }                          left=d[i+1];                  }              }          }          printf("%d %d\n",a1,a2);      return 0;  }