【HDU 1423】Greatest Common Increasing Subsequence【LCIS 裸题】

最朴素的算法

#include<bits/stdc++.h>
using namespace std;
int lenA,lenB,T;
int a[510],b[510];
int dp[510][510];
/*
状态：
a数组 考虑到i
b数组 考虑到j且以j结尾
*/
int main(void)
{
ios::sync_with_stdio(false);
cin>>T;
while(T--)
{
memset(dp,0,sizeof(dp));
cin>>lenA;
for(int i=1;i<=lenA;i++)cin>>a[i];
cin>>lenB;
for(int i=1;i<=lenB;i++)cin>>b[i];
for(int i=1;i<=lenA;i++)
{
for(int j=1;j<=lenB;j++)
{
dp[i][j] = dp[i-1][j];
if(a[i]==b[j])
{
int Max = 0;
for(int k=1;k<j;k++)if(b[j]>b[k])
{
Max = max(Max,dp[i-1][k]);
}
dp[i][j] = Max+1;
}

}
}
int ans = 0;
for(int i=1;i<=lenB;i++)ans = max(ans,dp[lenA][i]);
cout<<ans<<endl;
if(T)cout<<endl;
}
return 0;
}

优化！

#include<bits/stdc++.h>
using namespace std;
int lenA,lenB,T;
int a[510],b[510];
int dp[510][510];
/*
状态：
a数组 考虑到i
b数组 考虑到j且以j结尾
*/
int main(void)
{
ios::sync_with_stdio(false);
cin>>T;
while(T--)
{
cin>>lenA;
for(int i=1;i<=lenA;i++)cin>>a[i];
cin>>lenB;
for(int i=1;i<=lenB;i++)cin>>b[i];
for(int i=1;i<=lenA;i++)
{
int Max = 0;
for(int j=1;j<=lenB;j++)
{
dp[i][j] = dp[i-1][j];
if(a[i]>b[j])Max = max(Max,dp[i-1][j]);
if(a[i]==b[j])dp[i][j] = Max+1;
}
}
int ans = 0;
for(int i=1;i<=lenB;i++)ans = max(ans,dp[lenA][i]);
cout<<ans<<endl;
if(T)cout<<endl;
}
return 0;
}


空间优化
#include <stdio.h>
#include <string.h>

#define MAX 501

int T;
int seq1[MAX], seq2[MAX];
int len1, len2;
int dp[MAX];

int LCIS(){
int i, j;
int Max;
memset(dp, 0, sizeof(dp));
for (i = 1; i <= len1; ++i){
Max = 0;
for (j = 1; j <= len2; ++j){
if (seq1[i] > seq2[j] && Max < dp[j])
Max = dp[j];
if (seq1[i] == seq2[j])
dp[j] = Max + 1;
}
}
Max = 0;
for (i = 1; i <= len2; ++i){
if (Max < dp[i])
Max = dp[i];
}
return Max;
}

int main(void){
int i;
scanf("%d", &T);
while (T-- != 0){
scanf("%d", &len1);
for (i = 1; i <= len1; ++i)
scanf("%d", &seq1[i]);
scanf("%d", &len2);
for (i = 1; i <= len2; ++i)
scanf("%d", &seq2[i]);
printf("%d\n", LCIS());
if (T)
putchar('\n');
}

return 0;
}