【SPOJ】AIBOHP - Aibohphobia

Problem here

Solution

答案＝原字串長度-原字串與其反轉後字串的lcm

一開始用top down寫，TLE orz….
之後改成 bottom up 才AC

#include 
#include 
using namespace std;
string input, res;
int lcs[6101][6101];

int main(){

    int kase;
    cin >> kase;
    while(kase--){
        cin >> input;
        res.resize(input.size());
        for(int i = 0; i < input.length(); i++)
            res[i] = input[input.length()-1-i];

        for(int m = 0; m <= input.length(); m++){
            for(int n = 0; n <= res.length(); n++){
                if(m == 0 || n == 0)
                    lcs[m][n] = 0;
                else if(input[m-1] == res[n-1])
                    lcs[m][n] = 1 + lcs[m-1][n-1];
                else
                    lcs[m][n] = max(lcs[m][n-1], lcs[m-1][n]);
            }
        }

        cout << input.length() - lcs[input.length()][res.length()] << endl;
    }

    return 0;
}