题意:给 C 和 D 两个串
求 S(C,D) S(C,D) as 4⋅LCS(C,D)−|C|−|D|4⋅LCS(C,D)−|C|−|D|
if(c[i] == d[i]) 贡献+2;
else 贡献 - 1;
#include <iostream> #include <stdio.h> #include <string.h> #include <stack> #include <queue> #include <map> #include <set> #include <vector> #include <math.h> #include <bitset> #include <algorithm> #include <climits> using namespace std; #define Pair pair<int, int> #define ULL unsigned long long #define LS l,mid,lson #define RS mid+1,r,rson #define MEM(a,x) memset(a,x,sizeof(a)) #define gcd(a,b) __gcd(a,b) #define ll long long #define N 1000005 #define EXP 1e-8 #define lowbit(x) (x&-x) #define girlfriend zy #define E exp(1.0) //#define int long long const int maxn = 100001; const int MOD = 1e9 + 7; const int INF = 0x3f3f3f3f; int dp[5001][5001]; char s1[5001]; char s2[5001]; int dp[5001][5001]; char s1[5001]; char s2[5001]; int main() { int n,m; cin>>n>>m; cin>>s1+1>>s2+1; //脚标从1开始 dp[0][0] = 0; int ans = 0; for(int i=1;i<=n;i++) { for(int j=1;j<=m;j++) { if(s1[i] == s2[j]) { dp[i][j] = max(0,dp[i-1][j-1]) + 2; } else { dp[i][j] = max(dp[i][j-1],dp[i-1][j]) - 1; } ans = max(dp[i][j],ans); } } cout<<ans<<endl; }