Uva11235 (frequent values) (hdu1806)

Address: frequent values

 

Theme and solution ideas: see the White Paper p198.

 

Code:

 1 #include <stdio.h> 2 #include <string.h> 3 #include <math.h> 4 #include <algorithm> 5 #include <vector> 6 using namespace std; 7 const int M=100100; 8 int a[M]; 9 int val[M],cnt[M];10 int num[M],left[M],right[M];11 int d[M][20];12 int id;13 void RMQ_init(int A[])14 {15     int i,j;16     for(i=0; i<id; i++)17         d[i][0]=A[i];18     for(j=1; (1<<j)<=id; j++)19         for(i=0; i+(1<<j)-1<id; i++)20             d[i][j]=max(d[i][j-1],d[i+(1<<(j-1))][j-1]);21 }22 int RMQ(int L,int R)23 {24     int k=0;25     while((1<<(k+1))<=R-L+1)26         k++;27     return max(d[L][k],d[R-(1<<k)+1][k]);28 }29 int main()30 {31     int n;32     while(scanf("%d",&n)&&n)33     {34         int q;35         scanf("%d",&q);36         int i,j;37         id=0;38         scanf("%d",&a[1]);39         val[++id]=a[1];40         left[id]=1;41         int xu=1;42         num[1]=xu;43         for(i=2; i<=n; i++)44         {45             scanf("%d",&a[i]);46             if (a[i]!=a[i-1])47             {48                 val[++id]=a[i];49                 left[id]=i;50                 right[id-1]=i-1;51                 cnt[id-1]=i-left[id-1];52                 xu++;53             }54             num[i]=xu;55         }56         right[id]=i-1;57         cnt[id]=i-left[id];58         RMQ_init(cnt);59         int xu1,xu2;60         int  sum1=0,sum2=0,sum3=0,sum=0;61         while(q--)62         {63             int x,y;64             scanf("%d%d",&x,&y);65             xu1=num[x];66             xu2=num[y];67             if (xu1!=xu2)68             {69                 sum1=right[xu1]-x+1;70                 sum3=y-left[xu2]+1;71                 sum=sum1;72                 if (sum<sum3)73                     sum=sum3;74                 if (xu1+1<=xu2-1)75                 {76                     sum2=RMQ(xu1+1,xu2-1);77                     if (sum<sum2)78                         sum=sum2;79                 }80             }81             else82             {83                 sum=y-x+1;84             }85             printf("%d\n",sum);86         }87     }88     return 0;89 }90 /*91 10 392 -1 -1 1 1 1 1 3 10 10 1093 2 394 1 1095 5 1096 097 98 */

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Uva11235 (frequent values) (hdu1806)