CF 4D Mysterious Present

dfs题！！用Dp！可是就这么简单的思路，我偏偏绕远路，用LCS来DP求，被无情的MLE！

#include<iostream>#include<cstring>using namespace std;int dfs(int);int w[5001],h[5001],d[5001],p[5001],n;main(){cin>>n;for(int i=0;i<=n;i++)cin>>w[i]>>h[i];memset(d,0,sizeof(d));int k=dfs(0);cout<<k<<"\n";int i=0;while(p[i]){cout<<p[i]<<" ";i=p[i];}}int dfs(int x){if(d[x])return d[x];for(int i=0;i<=n;i++){if(w[i]>w[x] && h[i]>h[x]){int t=dfs(i);if(d[x]<t+1){d[x]=t+1;p[x]=i;}}}return d[x];}

我的MLE代码～

#include <iostream>#include <algorithm>#include <stdio.h>#include <string.h>using namespace std;struct Pair{    int v,id;}w[5010],h[5010];bool cmp(Pair a,Pair b){    return a.v < b.v;}int  dp[5010][5010],ww[5010],hh[5010],r[5010][5010],cot[5010],k = 0;bool a[1000010];void print(int i,int j){    if(i == 0||j == 0) return;    if(r[i][j] == 3) {print(i-1,j-1);cot[k++] = ww[i];}    else if(r[i][j] == 2) print(i-1,j);    else print(i,j-1);}int main(){    //freopen("a.txt","r",stdin);    int n,i,ans = 0,ii,jj,j,k1,k2;    cin>>n>>w[0].v>>h[0].v;    //int s[5010];    memset(dp,0,sizeof(dp));    w[0].id = 0;h[0].id = 0;    for(i = 1;i <= n;i ++)    {        cin>>w[i].v >>h[i].v;        w[i].id = h[i].id = i;        //cout<<"dsa"<<endl;    }    sort(w,w + n+1,cmp);    sort(h,h + n+1,cmp);    k1 = 0;k2 = 0;    memset(a,0,sizeof(a));    //cout<<"dsa"<<endl;    for(i = 0;i <= n;i ++)    if(w[i].id == 0) break;    while(i <= n) {if(a[w[i].v]==0){ww[k1++] = w[i].id;a[w[i].v] = 1;}i ++;}    //cout<<k1<<k2<<endl;    memset(a,0,sizeof(a));    for(i = 0;i <= n;i ++)    if(h[i].id == 0) break;    while(i <= n) {if(a[h[i].v]==0){hh[k2++] = h[i].id;a[h[i].v] = 1;}i ++;}    //cout<<k1<<k2<<endl;    for(i = 0;i < 5010;i ++) {dp[i][0] = 0;dp[0][i] = 0;}    for(i = 1;i < k1;i ++)    {        for(j = 1;j < k2;j ++)        {            if(ww[i] == hh[j]) {dp[i][j] = dp[i-1][j-1]+1;r[i][j] = 3;}            else if(dp[i-1][j] >= dp[i][j-1]) {dp[i][j] = dp[i-1][j];r[i][j] = 2;}            else {dp[i][j] = dp[i][j-1];r[i][j] = 1;}        }    }    //cout<<k1<<k2<<endl;    cout<<dp[k1-1][k2-1]<<endl;    print(k1-1,k2-1);    if(k > 0) cout<<cot[0];    for(i = 1;i < k;i ++) cout<<" "<<cot[i];}