一周总结08/30

1.最短路变形

【题意】给一个图,每条边有个距离和花费,要求创建一个子图,满足0点到其余点的距离总和最小,且边的总花费最小。

 【注意】首先,数组要开<<1大;

其次,双关键字的最短路,即最小花费下最短路,要注意优先级就是贪心,可以在优先队列做文章,也可以直接在松弛判断当两条边相同,选择当前花费更加小的代价

#include<cstdio>
#include<string>
#include<cstdlib>
#include<cmath>
#include<iostream>
#include<cstring>
#include<set>
#include<queue>
#include<algorithm>
#include<vector>
#include<map>
#include<cctype>
#include<stack>
#include<sstream>
#include<list>
#include<assert.h>
#include<bitset>
#include<numeric>
#define debug() puts("++++")
#define gcd(a,b) __gcd(a,b)
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
#define fi first
#define se second
#define pb push_back
#define sqr(x) ((x)*(x))
#define ms(a,b) memset(a,b,sizeof(a))
#define sz size()
#define be begin()
#define pu push_up
#define pd push_down
#define cl clear()
#define lowbit(x) -x&x
#define all 1,n,1
#define rep(i,x,n) for(int i=(x); i<(n); i++)
#define in freopen("in.in","r",stdin)
#define out freopen("out.out","w",stdout)
using namespace std;
typedef long long LL;
typedef unsigned long long ULL;
typedef pair<int,int> P;
const int INF = 0x3f3f3f3f;
const LL LNF = 1e18;
const int maxn = 500100;
const int maxm = 1e6+10;
const double PI = acos(-1.0);
const double eps = 1e-8;
const int dx[] = {-1,1,0,0,1,1,-1,-1};
const int dy[] = {0,0,1,-1,1,-1,1,-1};
int dir[4][2] = {{0,1},{0,-1},{-1,0},{1,0}};
const int mon[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
const int monn[] = {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
struct node
{
    int u,v,w,nxt,val;
}e[maxn<<2];
int head[maxn];
LL dis[maxn],cost[maxn];
bool vis[maxn];
int n,m,t,tot;
void init()
{
    tot=0;
    ms(head,-1);
    ms(dis,INF);
    ms(cost,INF);
    ms(vis,0);
}
void add(int u,int v,int w,int val)
{
    e[tot].v=v;
    e[tot].w=w;
    e[tot].val=val;
    e[tot].nxt=head[u];
    head[u]=tot++;
}
void spfa()
{
    queue<int> q;
    dis[0]=0; vis[0]=1; //cost[0]=0;
    q.push(0);
    while(!q.empty())
    {
        int u=q.front();
        q.pop();
        vis[u]=0;
        for(int i=head[u]; i!=-1; i=e[i].nxt)
        {
            int v=e[i].v;
            int w=e[i].w;
            int val=e[i].val;
            if( dis[v]>dis[u]+w || ( dis[v]==dis[u]+w && cost[v]>val ) )
            {
                dis[v]=dis[u]+w;
                cost[v]=val;
                if(!vis[v])
                {
                    vis[v]=1;
                    q.push(v);
                }
            }
        }
    }
}
int main()
{
    scanf("%d",&t);
    while(t--)
    {
        init();
        scanf("%d%d",&n,&m);
        for(int i=0;i<m;i++)
        {
            int u,v,w,val;
            scanf("%d%d%d%d",&u,&v,&w,&val);
            add(u,v,w,val);
            add(v,u,w,val);
        }
        spfa();
        LL s1=0,s2=0;
        for(int i=1;i<n;i++)
        {
            s1+=dis[i];
            s2+=cost[i];
        }
        printf("%lld %lld\n",s1,s2);
    }
}
/*
2
4 5
0 3 1 1
0 1 1 1
0 2 10 10
2 1 1 1
2 3 1 2
4 5
0 3 1 1
0 1 1 1
0 2 10 10
2 1 2 1
2 3 1 2

*/
ZOJ K - Highway Project

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转载自www.cnblogs.com/Roni-i/p/9557891.html