bzoj2662冻结

题目链接

话说为什么出题人老是卡$SPFA$啊$qwq$

然而$SPFA$硬是让本宝宝写成了$dij$

分情况讨论就好

/**************************************************************
    Problem: 2662
    User: zhangheran
    Language: C++
    Result: Accepted
    Time:12 ms
    Memory:1356 kb
****************************************************************/

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<queue>
using namespace std;
int n,m,k;
struct data{
    int u;int v;int value;int next;
}edge[];int alist[];
int cnt;
void add(int u,int v,int value)
{
    edge[cnt].v=v;
    edge[cnt].u=u;
    edge[cnt].value=value;
    edge[cnt].next=alist[u];
    alist[u]=cnt++;
    return ;
}
struct node{int u;int v;};
queue<node> q;
int d[][];
bool ins[][];
void spfa()
{
    d[][]=;
    ins[][]=true;
    q.push((node){,});
    while(!q.empty())
    {
        node x=q.front();
        q.pop();
        ins[x.u][x.v]=false;
        int next=alist[x.v];
        while(next!=-)
        {
            int v=edge[next].v;
            if(d[x.u][v]>d[x.u][x.v]+edge[next].value){
                d[x.u][v]=d[x.u][x.v]+edge[next].value;
                if(!ins[x.u][v])
                    ins[x.u][v]=true,
                    q.push((node{x.u,v}));
            }
            next=edge[next].next;
        }
        if(x.u<k){
            int next=alist[x.v];
            while(next!=-){
                int v=edge[next].v;
                if(d[x.u+][v]>d[x.u][x.v]+edge[next].value/){
                    d[x.u+][v]=d[x.u][x.v]+edge[next].value/;
                    if(!ins[x.u+][v])
                        ins[x.u+][v]=true,
                        q.push((node){x.u+,v});
                }
                next=edge[next].next;
            }
        }
    }
}
int u,v,value;
int main()
{
    scanf("%d%d%d",&n,&m,&k);
    memset(d,0x3f3f3f3f,sizeof(d));
    memset(alist,-,sizeof(alist));
    for(int i=;i<=m;i++)
        scanf("%d%d%d",&u,&v,&value),
        add(u,v,value),
        add(v,u,value);
    spfa();
    int minn=0x3f3f3f3f;
    for(int i=;i<=k;i++) minn=min(minn,d[i][n]);
    printf("%d",minn);
    return ;
}