POJ 2886 Who Gets the Most Candies?(树状数组+二分)

题目链接

注意题目中给的顺序是顺时针的，所以在数组中应该是倒着存的。左就是顺时针，右就是逆时针。各种调试之后，终于A了，很多种情况考虑情况。

 #include <cstring>
 #include <cstdio>
 #include <string>
 #include <iostream>
 #include <algorithm>
 #include <vector>
 using namespace std;
 char name[][];
 int o[];
 int p[];
 int s[];
 int n;
 int lowbit(int t)
 {
     return t&(-t);
 }
 void insert(int t,int d)
 {
     while(t <= n)
     {
         p[t] += d;
         t += lowbit(t);
     }
 }
 int getsum(int t)
 {
     int sum = ;
     while(t > )
     {
         sum += p[t];
         t -= lowbit(t);
     }
     return sum;
 }
 int find(int x)
 {
     int str,mid,end,temp;
     str = ;end = n;
     while(str < end)
     {
         mid = (str+end)/;
         temp = getsum(mid);
         if(temp < x)
         str = mid + ;
         else
         end = mid;
     }
     return str;
 }
 int main()
 {
     int i,k,j,maxz,sum,sl,sr,key;
     while(scanf("%d%d",&n,&k)!=EOF)
     {
         for(i = n; i >= ; i --)
         {
             scanf("%s%d",name[i],&s[i]);
         }
         for(i = ;i <= n;i ++)
         {
             p[i] = ;
             o[i] = ;
         }
         for(i = ;i <= n;i ++)
         {
             for(j = i;j <= n;j += i)
             {
                 o[j] ++;
             }
         }
         maxz = ;
         key = ;
         for(i = ;i <= n;i ++)
         {
             if(maxz < o[i])
             {
                 maxz = o[i];
                 key = i;
             }
         }
         for(i = ; i <= n; i ++)
         {
             insert(i,);
         }
         k = n - k + ;
         insert(k,-);
         sum = n-;
         for(i = ;i <= key;i ++)
         {
             sl = getsum(k);
             sr = sum - sl;
             if(s[k] > )
             {
                 s[k] = s[k]%sum;
                 if(s[k] == ) s[k] = sum;
                 if(sl >= s[k])
                 k = find(sl-s[k]+);
                 else
                 k = find(sum-(s[k]-sl)+);
             }
             else
             {
                 s[k] = -s[k];
                 s[k] = (s[k])%sum;
                 if(s[k] == ) s[k] = sum;
                 if(sr >= s[k])
                 k = find(sl+s[k]);
                 else
                 k = find(s[k]-sr);
             }
             insert(k,-);
             sum --;
         }
         printf("%s %d\n",name[k],o[key]+);
     }
     return ;
 }