WA 40分qwq 卖个萌，啊呜

#include<cstdio>
#include<iostream>
using namespace std;

const int INF = 1e8 + 17;
const int MAXN = 2e3 + 17;

int n,m,v,e;
int c[MAXN],d[MAXN];
double K[MAXN],dis[MAXN][MAXN],F[MAXN][MAXN][2];

int main()
{
	cin >> n >> m >> v >> e;
	for(int i = 1;i <= n;i += 1)
		cin >> c[i];
	for(int i = 1;i <= n;i += 1)
		cin >> d[i];
	for(int i = 1;i <= n;i += 1)
		cin >> K[i];
	for(int i = 1;i <= v;i += 1)
		for(int j = 1;j <= v;j += 1)
			dis[i][j] = INF;
	for(int i = 1,u,V;i <= e;i += 1)
	{
		double w;
		cin >> u >> V >> w;
		dis[u][V] = dis[V][u] = min(dis[u][V],w);
	}
	for(int i = 1;i <= v;i += 1)
		dis[i][i] = 0;
	for(int k = 1;k <= v;k += 1)
		for(int i = 1;i <= v;i += 1)
			for(int j = 1;j <= v;j += 1)
				if(dis[i][k] + dis[k][j] < dis[i][j])dis[i][j] = dis[i][k] + dis[k][j];
	for(int i = 1;i <= n;i += 1)
		for(int j = 0;j <= min(i,m);j += 1)
			F[i][j][0] = F[i][j][1] = INF;
	F[1][0][0] = F[1][1][1] = 0;
	for(int i = 2;i <= n;i += 1)
	{
		F[i][0][0] = F[i - 1][0][0] + dis[c[i - 1]][c[i]];
		for(int j = 1;j <= min(m,i);j += 1)
		{
			F[i][j][0] = min(F[i - 1][j][1] + (1 - K[i - 1]) * dis[c[i - 1]][c[i]] + K[i - 1] * dis[d[i - 1]][c[i]],
							 F[i - 1][j - 1][0] + dis[c[i - 1]][c[i]]);
			F[i][j][1] = min(F[i - 1][j - 1][0] + (1 - K[i]) * dis[c[i]][c[i - 1]] + K[i] * dis[d[i]][c[i - 1]],
							 F[i - 1][j - 1][1] + (1 - K[i - 1]) * (1 - K[i]) * dis[c[i]][c[i - 1]] + (1 - K[i - 1]) * K[i] * dis[c[i - 1]][d[i]] +
							 K[i - 1] * (1 - K[i]) * dis[d[i - 1]][c[i]] + K[i - 1] * K[i] * dis[d[i]][d[i - 1]]);
		}
	}
	double ans = INF;
	for(int i = 0;i <= m;i += 1)
		ans = min(ans,min(F[n][i][0],F[n][i][1]));
	printf("%.2lf\n",ans);
	return 0;
}