lcs

Posted 2021-02-08 zhibin123

 

lcs

刚刚重新学了一种模板。

#include<bits/stdc++.h>
using namespace std;
int fcs(const char *ts1,const char *ts2,string & str){//参数传入char * 和引用
    int l1 = strlen(ts1);
    int l2 = strlen(ts2);
    const char * s1 = ts1 - 1;//这里用于将char数组前移一位，方便后面操作。下标1对应第一个char
    const char * s2 = ts2 - 1;
    int m[101][101] = {0};
    int i,j;
    for(i = 1;i <= l1;i++){
        for(j = 1; j <= l2;j++){
            m[i][j] = max(m[i-1][j],m[i][j-1]);
            if(s1[i] == s2[j]){
                m[i][j] = max(m[i][j],m[i-1][j-1]+1);
            }
        }
    }
//后面求出最长公共子序列
    i = l1,j = l2;
    while(i != 0 && j!=0 ){
        if(s1[i] == s2[j]){
            str.push_back(s1[i]);
            i--;
            j--;
        }else{
            if(m[i-1][j] > m[i][j-1]){
                i--;
            }else{
                j--;
            }
        }
    }
    reverse(str.begin(),str.end());
    return m[l1][l2];//返回长度
}
int main()
{
    const char *s1 = "abcdef";
    const char *s2 = "bcdefg";
    string s;
    cout << fcs(s1,s2,s) << endl;
    cout << s << endl;
    return 0;
}