最长公共子序列(longest common sequence):可以不连续 最长公共子串(longest common substring):连续 demo for (int i = 1;i<=lena;i++){ for (int j = 1;j<=lenb;j++){ if(a[i-1]==b[j-1]){ dp[i][j]=dp[i-1][j-1]+1; }else{ dp[i][j]=max(dp[i-1][j],dp[i][j-1]); } }