动态规划：最长子序列问题

<span style="font-size:24px;">import java.util.*;

public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int N = sc.nextInt();

while (N-- > 0) {
String str1 = sc.next();
// String str2=sc.next();
StringBuffer sb = new StringBuffer(str1);
String str2 = sb.reverse().toString();
int length1 = longest(str1, str2);
System.out.println(str1.length() - length1);
// System.out.println(length1);
}
}

public static int longest(String str1, String str2) {
char[] s1 = str1.toCharArray();
// char[] s2=new StringBuffer(s).reverse().toString().toCharArray();
char[] s2 = str2.toCharArray();
int m = s1.length;
int n = s2.length;
int[][] dp = new int[m]
;
dp[0][0] = s1[0] == s2[0] ? 1 : 0;
for (int i = 1; i < n; i++) {
dp[0][i] = Math.max(dp[0][i - 1], s1[0] == s2[i] ? 1 : 0);
}
for (int i = 1; i < m; i++) {
dp[i][0] = Math.max(dp[i - 1][0], s1[i] == s2[0] ? 1 : 0);
}
for (int i = 1; i < m; i++) {
for (int j = 1; j < n; j++) {
if (s1[i] == s2[j])
dp[i][j] = dp[i - 1][j - 1] + 1;
else
dp[i][j] = Math.max(dp[i - 1][j], dp[i][j - 1]);
}
}
return dp[m - 1][n - 1];
}
}
</span>