蓝桥集训之松散子序列

• 核心思想：状态机+dp

  • 

  • 每个点两种状态

  • f[i,0] = max(f[i-1,0] , f[i-1,1])

  • f[i,1] = f[i-1,0] + w;

•   #include <iostream>
    #include <cstring>
    #include <algorithm>
    
    using namespace std;
    
    const int N = 1000010;
    int f[N][2];
    int n;
    char str[N];
    
    int main()
    {
        cin>>str+1;
        n = strlen(str+1);
        for(int i=1;i<=n;i++)
        {
            f[i][0] = max(f[i-1][0] , f[i-1][1]);
            f[i][1] = f[i-1][0] + str[i] - 'a' + 1;
        }
        cout<<max(f[n][0] , f[n][1])<<endl;
        return 0;
    }