mirror of
https://github.com/Kiritow/OJ-Problems-Source.git
synced 2024-03-22 13:11:29 +08:00
100 lines
1.3 KiB
C++
100 lines
1.3 KiB
C++
#include <iostream>
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#include <cstdio>
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#include <cstring>
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#include <cmath>
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#define maxn 300001
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#define eps 1e-6
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using namespace std;
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int n;
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int m;
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int len[maxn];
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int vis[maxn];
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int mx[maxn][24];
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int pre[maxn];
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int search(int l,int r)
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{
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int t=l;
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while(l<r)
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{
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int mid=l+r>>1;
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if(pre[mid]<t)
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{
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l=mid+1;
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}
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else
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{
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r=mid;
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}
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}
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return l;
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}
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void init_rmq()
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{
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int i,j;
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int k=(int)(log2(n)+eps);
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for(i=1; i<=n; i++)
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{
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mx[i][0]=len[i];
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}
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for(i=1; i<=k; i++)
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{
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for(j=1; j<=n; j++)
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{
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mx[j][i]=mx[j][i-1];
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if(j+(1<<(i-1))<=n)
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{
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mx[j][i]=max(mx[j][i],mx[j+(1<<(i-1))][i-1]);
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}
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}
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}
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}
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int rmq(int l,int r)
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{
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int k=(int)(log2(r-l+1)+eps);
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return max(mx[l][k],mx[r-(1<<k)+1][k]);
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}
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int main()
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{
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int i,j;
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while(scanf("%d",&n)!=EOF)
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{
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memset(len,0,sizeof(len));
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memset(vis,-1,sizeof(vis));
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memset(pre,-1,sizeof(pre));
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for(i=1; i<=n; i++)
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{
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int temp;
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scanf("%d",&temp);
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if(vis[temp]==-1)
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{
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pre[i]=1;
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}
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else
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{
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pre[i]=vis[temp]+1;
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}
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pre[i]=max(pre[i],pre[i-1]);
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len[i]=i-pre[i]+1;
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vis[temp]=i;
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}
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init_rmq();
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scanf("%d",&m);
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while(m--)
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{
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int l,r;
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scanf("%d %d",&l,&r);
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if(l>r) swap(l,r);
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int t=search(l,r);
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if(t==r)
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{
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printf("%d\n",t-l+1);
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}
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else
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{
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printf("%d\n",max(t-l,rmq(t,r)));
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}
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}
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}
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return 0;
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}
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