@interface LongestCommonSubsequence : NSObject <NSString *> { // 两个输入字符串 NSString *str1; NSString *str2; }

• (NSString *)longestCommonSubsequence:(NSString *)str1 str2:(NSString *)str2 { // 初始化动态规划数组 NSInteger n = str1.length; NSInteger m = str2.length; NSInteger **dp = (NSInteger **)malloc((n+1) * (m+1)); for (NSInteger i = 0; i <= n; i++) { for (NSInteger j = 0; j <= m; j++) { dp[i][j] = 0; } }

  // 填充动态规划表 for (NSInteger i = 1; i <= n; i++) { for (NSInteger j = 1; j <= m; j++) { if (str1[i-1] == str2[j-1]) { dp[i][j] = dp[i-1][j-1] + 1; } else { dp[i][j] = max(dp[i-1][j], dp[i][j-1]); } } }

  return [NSString stringWithFormat:@"%ld", dp[n][m]]; }

 
     
  该实现通过动态规划方法有效地解决了最长公共子序列问题，能够处理较长的输入字符串，并返回最长公共子序列的长度。