【最短路】codevs 1391 伊吹萃香

[code]#include <iostream>
#include <cstdio>
#include <cstring>
#include <queue>
using namespace std;
struct Link
{
    int s,t,c,next;
}l[50000];
struct qu
{
    int x,b;
};
bool b[6000];
int w[6000];
int r[6000];
int g[6000];
int dp[6000][3];
int cnt = 0;
queue<qu> Q;

int value(int x)
{
    if(x < 0)
        return 0;
    return x;
}

int abs(int x)
{
    if(x < 0)
        return -x;
    return x;
}

void Add_Link(int s,int t,int c)
{
    l[++cnt].s = s;
    l[cnt].t = t;
    l[cnt].c = c;
    l[cnt].next = g[s];
    g[s] = cnt;
}

void update(qu p)
{
    int x = p.x;
    bool now = p.b;
    int q = g[x];
    if(now)
    {
        if(dp[x][0] > dp[x][1] + r[x])
        {
            dp[x][0] = dp[x][1] + r[x];
            Q.push((qu){x,0});
        }
        while(q)
        {
            bool k = b[l[q].t]^b[x]^now;
            if(k == 0 && dp[l[q].t][1] > dp[x][1] + value(l[q].c + abs(w[l[q].t] - w[x])))
            {
                dp[l[q].t][1] = dp[x][1] + value(l[q].c + abs(w[l[q].t] - w[x]));
                Q.push((qu){l[q].t,1});
            }
            if(k == 1 && dp[l[q].t][0] > dp[x][1] + l[q].c)
            {
                dp[l[q].t][0] = dp[x][1] + l[q].c;
                Q.push((qu){l[q].t,0});
            }
            q = l[q].next;
        }
    }
    else
    {
        if(dp[x][1] > dp[x][0])
        {
            dp[x][1] = dp[x][0];
            Q.push((qu){x,1});
        }
        while(q)
        {
            bool k = b[l[q].t]^b[x]^now;
            if(k == 1 && dp[l[q].t][0] > dp[x][0] + value(l[q].c - abs(w[l[q].t] - w[x])))
            {
                dp[l[q].t][0] = dp[x][0] + value(l[q].c - abs(w[l[q].t] - w[x]));
                Q.push((qu){l[q].t,0});
            }
            if(k == 0 && dp[l[q].t][1] > dp[x][0] + l[q].c)
            {
                dp[l[q].t][1] = dp[x][0] + l[q].c;
                Q.push((qu){l[q].t,1});
            }
            q = l[q].next;
        }
    }
}

int main()
{
    int n,m,s,t,c;
    scanf("%d%d",&n,&m);
    for(int i = 1;i <= n;i ++)
        scanf("%d",&b[i]);
    for(int i = 1;i <= n;i ++)
        scanf("%d",&w[i]);
    for(int i = 1;i <= n;i ++)
        scanf("%d",&r[i]);
    for(int i = 1;i <= m;i ++)
    {
        scanf("%d%d%d",&s,&t,&c);
        Add_Link(s,t,c);
    }
    memset(dp,63,sizeof(dp));
    dp[1][b[1]] = 0;
    Q.push((qu){1,b[1]});
    while(!Q.empty())
    {
        qu x = Q.front();
        Q.pop();
        update(x);
    }
    cout << min(dp
[0],dp
[1]);
    return 0;
}