Given a string S and a string T, count the number of distinct subsequences of T in S.
A subsequence of a string is a new string which is formed from the original string by deleting some (can be none) of the characters without disturbing the relative positions of the remaining characters. (ie,"ACE"is a subsequence of"ABCDE"while"AEC"is not).
Here is an example: S ="rabbbit", T ="rabbit"
Return3.
C++
class Solution { public: int numDistinct(string S, string T) { S=" "+S,T=" "+T; int n=S.length(); int m=T.length(); int i; int j; vector<vector<int> > dp(n+1,vector<int>(m+1,0)); for(i=0;i<=n;i++) dp[i][0]=1; for(i=1;i<=n;i++) for(j=1;j<=m;j++){ dp[i][j]=dp[i-1][j]; if(S[i]==T[j]) dp[i][j]+=dp[i-1][j-1]; } return dp[n][m]; } };
转载于:https://www.cnblogs.com/vercont/p/10210285.html
相关资源：JAVA上百实例源码以及开源项目