PAT A1045 . Favorite Color Stripe (30)

Eva is trying to make her own color stripe out of a given one. She would like to keep only her favorite colors in her favorite order by cutting off those unwanted pieces and sewing the remaining parts together to form her favorite color stripe.

It is said that a normal human eye can distinguish about less than 200 different colors, so Eva’s favorite colors are limited. However the original stripe could be very long, and Eva would like to have the remaining favorite stripe with the maximum length. So she needs your help to find her the best result.

Note that the solution might not be unique, but you only have to tell her the maximum length. For example, given a stripe of colors {2 2 4 1 5 5 6 3 1 1 5 6}. If Eva’s favorite colors are given in her favorite order as {2 3 1 5 6}, then she has 4 possible best solutions {2 2 1 1 1 5 6}, {2 2 1 5 5 5 6}, {2 2 1 5 5 6 6}, and {2 2 3 1 1 5 6}.

Input Specification:

Each input file contains one test case. For each case, the first line contains a positive integer N (<=200) which is the total number of colors involved (and hence the colors are numbered from 1 to N). Then the next line starts with a positive integer M (<=200) followed by M Eva’s favorite color numbers given in her favorite order. Finally the third line starts with a positive integer L (<=10000) which is the length of the given stripe, followed by L colors on the stripe. All the numbers in a line are separated by a space.

Output Specification:

For each test case, simply print in a line the maximum length of Eva’s favorite stripe.

Sample Input:
6
5 2 3 1 5 6
12 2 2 4 1 5 5 6 3 1 1 5 6
Sample Output:
7

lis:

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#include "stdio.h"
#include "algorithm"
using namespace std;

const int maxc = 210;//最大颜色数
const int maxn = 10010;//最大L
int hashTable[maxc];//将最喜欢的颜色序列映射为递增序列,不喜欢的颜色映射为-1
int A[maxn], dp[maxn];
int main(){
int n, m, x;
scanf("%d%d", &n, &m);
memset(hashTable, -1, sizeof(hashTable));
for (int i = 0; i < m; i++) {
scanf("%d", &x);
hashTable[x] = i;
}
int L, num = 0;//num存放颜色序列中eva最喜欢的颜色的总数
scanf("%d", &L);
for (int i = 0; i < L; i++) {
scanf("%d", &x);
if (hashTable[x] >= 0) {//若有喜欢的颜色,添加到数组A中
A[num++] = hashTable[x];
}
}
//以下全部为LIS问题模板
int ans = -1;
for (int i = 0; i < num; i++) {
dp[i] = 1;
for (int j = 0; j < i; j++) {
if (A[j] <= A[i] && dp[i] < dp[j] + 1) {
dp[i] = dp[j] + 1;
}
}
ans = max(ans, dp[i]);
}
printf("%d", ans);
return 0;
}

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#include "stdio.h"
#include "math.h"
#include "string.h"

const int maxc = 210;
const int maxn = 1000010;
int a[maxc], b[maxn], dp[maxc][maxn];
int main(){
int n, m;
scanf("%d%d", &n, &m);
for (int i = 1; i <= m ; i++) {
scanf("%d", &a[i]);//读入序列A
}
int L;
scanf("%d", &L);
for (int i = 1; i <= L; i++) {
scanf("%d", &b[i]);
}
//边界
for (int i = 0; i <= m; i++) {
dp[i][0] = 0;
}
for (int j = 0; j <= L; j++) {
dp[0][j] = 0;
}
//状态转移方程
for (int i = 1; i <= m; i++) {
for (int j = 1; j <= L; j++) {
//取dp[i-1][j]、dp[i][j-1]中的较大值
int MAX = max(dp[i - 1][j], dp[i][j - 1]);
if (a[i] == b[j]) {
dp[i][j] = MAX + 1;
}else{
dp[i][j] = MAX;
}
}
}
//输出答案
printf("%d\n", dp[m][L]);
return 0;
}