RMQ模板

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mb5fd86ac270497 2015-10-08 20:26:00

文章标签 #include i++ #define ios 最小值 文章分类 代码人生

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <string>
#include <map>
#include <stack>
#include <vector>
#include <set>
#include <queue>
#pragma comment (linker,"/STACK:102400000,102400000")
#define maxn 50005
#define MAXN 100005
#define mod 1000000009
#define INF 0x3f3f3f3f
#define pi acos(-1.0)
#define eps 1e-6
typedef long long ll;
using namespace std;

int n,m,ans,cnt,tot,flag;
int len,st,ed;   // 直徑 起點 終點
bool vis[maxn];
int head[maxn],val[maxn],dist[maxn][2];
int f[maxn][20],g[maxn][20],lg[maxn];  //第二維為二進位
struct Node
{
    int v,w,next;
} edge[MAXN];

void addedge(int u,int v,int w)
{
    cnt++;
    edge[cnt].v=v;
    edge[cnt].w=w;
    edge[cnt].next=head[u];
    head[u]=cnt;
}
void dfs(int u,int fa,int sum){
    if(sum>len){
      len=sum;
      st=u;
    }
    int i,j,v;
    for(i=head[u];i;i=edge[i].next){
        v=edge[i].v;
        if(v!=fa){
            dfs(v,u,sum+edge[i].w);
        }
    }
}
void dfs1(int u,int fa,int k,int sum){
    dist[u][k]=sum;
    int i,j,v;
    for(i=head[u];i;i=edge[i].next){
        v=edge[i].v;
        if(v!=fa)
         dfs1(v,u,k,sum+edge[i].w);
    }
}
void init_rmq()              // 預處理  O(n*log(n))
{
    int i,j;
    for(i=1;i<=n;i++)
    {
        f[i][0]=g[i][0]=val[i];
    }
    for(j=1;(1<<j)<=n;j++)
    {
        for(i=1;i+j-1<=n;i++)
        {
            if((i+(1<<(j-1))<=n))
            {
                f[i][j]=max(f[i][j-1],f[i+(1<<(j-1))][j-1]);  //避免越界
                g[i][j]=min(g[i][j-1],g[i+(1<<(j-1))][j-1]);
            }
            else
            {
                f[i][j]=f[i][j-1];
                g[i][j]=g[i][j-1];
            }
        }
    }
}
int query_rmq(int l,int r)
{
    int k=lg[r-l+1];
    return 
       max(f[l][k],f[r-(1<<k)+1][k])-min(g[l][k],g[r-(1<<k)+1][k]);
}
int main()
{
    int i,j,t;
    lg[1]=0;
    for(i=2;i<=50000;i++)
    {
        lg[i]=lg[i>>1]+1;
    }
    while(~scanf("%d%d",&n,&m))
    {
        if(n==0&&m==0) break ;
        cnt=0;
        memset(head,0,sizeof(head));
        int u,v,w;
        for(i=1;i<n;i++)
        {
            scanf("%d%d%d",&u,&v,&w);
            addedge(u,v,w);
            addedge(v,u,w);
        }
        len=0;
        dfs(1,0,0);
        ed=st;
        len=0;
        dfs(st,0,0);


        dfs1(st,0,0,0);
        dfs1(ed,0,1,0);

        for(i=1;i<=n;i++)
        {
            val[i]=max(dist[i][0],dist[i][1]);
        }
        init_rmq();
        int q,le,ri,mid,res,id;
        while(m--){
            scanf("%d",&q);
            ans=id=1;
            for(i=1;i<=n;i++)
            {
                while(id<=i){
                    res=query_rmq(id,i);
                    if(res>q)
                        id++;
                    else break ;
                }
                ans=max(ans,i-id+1);
            }
            printf("%d\n",ans);
        }
    }
    return 0;
}

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

int val[255][255];
int mm[255];
int dpmin[255][255][8][8];//最小值
int dpmax[255][255][8][8];//最大值

void initRMQ(int n,int m)
{
    for(int i = 1;i <= n;i++)
        for(int j = 1;j <= m;j++)
            dpmin[i][j][0][0] = dpmax[i][j][0][0] = val[i][j];
    for(int ii = 0; ii <= mm[n]; ii++)
        for(int jj = 0; jj <= mm[m]; jj++)
            if(ii+jj)
                for(int i = 1; i + (1<<ii) - 1 <= n; i++)
                    for(int j = 1; j + (1<<jj) - 1 <= m; j++)
                    {
                        if(ii)
                        {
                            dpmin[i][j][ii][jj] = min(dpmin[i][j][ii-1][jj],dpmin[i+(1<<(ii-1))][j][ii-1][jj]);
                            dpmax[i][j][ii][jj] = max(dpmax[i][j][ii-1][jj],dpmax[i+(1<<(ii-1))][j][ii-1][jj]);
                        }
                        else
                        {
                            dpmin[i][j][ii][jj] = min(dpmin[i][j][ii][jj-1],dpmin[i][j+(1<<(jj-1))][ii][jj-1]);
                            dpmax[i][j][ii][jj] = max(dpmax[i][j][ii][jj-1],dpmax[i][j+(1<<(jj-1))][ii][jj-1]);
                        }
                    }
}
//查询矩形的最大值
int rmq1(int x1,int y1,int x2,int y2)
{
    int k1 = mm[x2-x1+1];
    int k2 = mm[y2-y1+1];
    x2 = x2 - (1<<k1) + 1;
    y2 = y2 - (1<<k2) + 1;
    return max(max(dpmax[x1][y1][k1][k2],dpmax[x1][y2][k1][k2]),max(dpmax[x2][y1][k1][k2],dpmax[x2][y2][k1][k2]));
}
//查询矩形的最小值
int rmq2(int x1,int y1,int x2,int y2)
{
    int k1 = mm[x2-x1+1];
    int k2 = mm[y2-y1+1];
    x2 = x2 - (1<<k1) + 1;
    y2 = y2 - (1<<k2) + 1;
    return min(min(dpmin[x1][y1][k1][k2],dpmin[x1][y2][k1][k2]),min(dpmin[x2][y1][k1][k2],dpmin[x2][y2][k1][k2]));
}


int main()
{
    mm[0] = -1;
    for(int i = 1;i <= 500;i++)
        mm[i] = ((i&(i-1))==0)?mm[i-1]+1:mm[i-1];
    int N,B,K;
    for(int i=1;i<=250;i++){
        if(i%5==0)
            printf("\n");
        printf("%10d",mm[i]);
    }
    while(scanf("%d%d%d",&N,&B,&K)==3)
    {
        for(int i = 1;i <= N;i++)
            for(int j = 1;j <= N;j++)
                scanf("%d",&val[i][j]);
        initRMQ(N,N);
        int x,y;
        while(K--)
        {
            scanf("%d%d",&x,&y);
            printf("%d\n",rmq1(x,y,x+B-1,y+B-1)-rmq2(x,y,x+B-1,y+B-1));
        }
    }
    return 0;
}

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

const int MAXN = 100010;

int dp[MAXN][20];
int mm[MAXN];

void initRMQ(int n,int b[])
{
    mm[0] = -1;
    for(int i = 1;i <= n;i++)
    {
        mm[i] = ((i&(i-1)) == 0)?mm[i-1]+1:mm[i-1];
        dp[i][0] = b[i];
    }
    for(int j = 1;j <= mm[n];j++)
        for(int i = 1;i + (1<<j) - 1 <= n;i++)
            dp[i][j] = max(dp[i][j-1],dp[i+(1<<(j-1))][j-1]);
}
int rmq(int x,int y)
{
    int k = mm[y-x+1];
    return max(dp[x][k],dp[y-(1<<k)+1][k]);
}

int a[MAXN];
int hash[MAXN];
int L[MAXN],R[MAXN];
int b[MAXN];

int main()
{
    int n,m;
    while(scanf("%d",&n) == 1 && n)
    {
        scanf("%d",&m);
        for(int i = 1;i <= n;i++)
            scanf("%d",&a[i]);
            
            
        int k = 1;
        int l = 1;
        memset(b,0,sizeof(b));
        for(int i = 1;i <= n;i++)
        {
            if(i > 1 && a[i] != a[i-1])
            {
                for(int j = l;j < i;j++)
                {
                    L[j] = l;
                    R[j] = i-1;
                }
                b[k] = i - l;
                l = i;
                k ++;
            }
            hash[i] = k;
        }
        for(int j = l;j <= n;j++)
        {
            L[j] = l;
            R[j] = n;
        }
        b[k] = n-l+1;
        
        
        initRMQ(k,b);
        int u,v;
        while(m--)
        {
            scanf("%d%d",&u,&v);
            int t1 = hash[u];
            int t2 = hash[v];
            if(t1 == t2)
            {
                printf("%d\n",v-u+1);
                continue;
            }
            int ans = max(R[u]-u+1,v-L[v]+1);
            t1++;
            t2--;
            if(t1 <= t2)ans = max(ans,rmq(t1,t2));
            printf("%d\n",ans);
        }
    }
    return 0;
}