bnu 33971 Funny Car Racing （spfa）

来源：互联网发布：讲故事软件哪个好编辑：程序博客网时间：2024/05/16 03:23
类似最短路
#include<algorithm>#include<iostream>#include<cstdio>#include<cstring>#include<string>#include<vector>#include <queue>#define REP(i, n) for(int i=0; i<n; i++)#define FF(i, a, b) for(int i=a; i<b; i++)#define FD(i, a, b) for(int i=a; i>=b; i--)#define CLR(a, b) memset(a, b, sizeof(a))#define PB push_backusing namespace std;const int maxn = 100010;const int INF = 100000007;int n, m, s, t;struct  Node{    int to, next;    int at, bt, tt;};Node adj[50050];int head[310];int tot;void init(){    tot = 0;    CLR(head, -1);}void add_edge(int x, int y, int at, int bt, int tt){    adj[tot].to = y;    adj[tot].at = at;    adj[tot].bt = bt;    adj[tot].tt = tt;    adj[tot].next = head[x];    head[x] = tot++;}int dp[310];int inq[310];void spfa(){    REP(i, n + 1) dp[i] = INF;    dp[s] = 0;    CLR(inq, 0);    inq[s] = 1;    queue<int>q;    while (!q.empty()) q.pop();    q.push(s);    while (!q.empty())    {        int u = q.front(); q.pop();        inq[u] = 0;        for (int r = head[u]; r != -1; r = adj[r].next)        {            if (adj[r].at < adj[r].tt) continue;            int v = adj[r].to;            int y = dp[u] % (adj[r].at + adj[r].bt);            int x = adj[r].at - y;            if (x >= adj[r].tt)            {                int nextv = dp[u] + adj[r].tt;                if (dp[v] > nextv)                {                    dp[v] = nextv;                    if (!inq[v]) inq[v] = 1, q.push(v);                }            }            else            {                int nextv = dp[u] + adj[r].tt + (adj[r].at + adj[r].bt - y);                if (dp[v] > nextv)                {                    dp[v] = nextv;                    if (!inq[v]) inq[v] = 1, q.push(v);                }            }        }    }}int main(){    int nc = 1;    int at, bt, tt;    int x, y;    while (~scanf("%d%d%d%d", &n, &m, &s, &t))    {        init();        while (m--)        {            scanf("%d%d%d%d%d", &x, &y, &at, &bt, &tt);            add_edge(x, y, at, bt, tt);        }        spfa();        printf("Case %d: %d\n", nc++, dp[t]);    }}