牛客练习赛60 D.斩杀线计算大师 (同余最短路)

题目:传送门

题解:https://ac.nowcoder.com/discuss/394080?type=101&order=0&pos=1&page=1

 

#include<iostream>
#include<algorithm>
#include<cstdio>
#include<utility>
#include<cstring>
#include<functional>
#include<queue>
 
using namespace std;
 
typedef long long ll;
typedef pair<int, int> pii;
 
const int maxn = 1e5;
const int INF = 0x7fffffff;
 
ll dis[maxn + 5], k;
 
pii edge[maxn + 5];
int a, b, c;
ll res[10];
 
void dijkstra() {
    for (int i = 1; i <= c; ++i)dis[i] = INF;
    priority_queue<pii, vector<pii>, greater<pii>> q;
    q.push(pii(0, 0));
    while (!q.empty()) {
        pii u = q.top(); q.pop();
        if (u.first > dis[u.second])continue;
        if (dis[(u.second + a) % c] > dis[u.second] + a){
            dis[(u.second + a) % c] = dis[u.second] + a;
            edge[(u.second + a) % c] = pii(u.second, 1);
            q.push(pii(dis[(u.second + a) % c], (u.second + a) % c));
        }
        if (dis[(u.second + b) % c] > dis[u.second] + b) {
            dis[(u.second + b) % c] = dis[u.second] + b;
            edge[(u.second + b) % c] = pii(u.second, 2);
            q.push(pii(dis[(u.second + b) % c], (u.second + b) % c));
        }
    }
}
void dfs(int now) {
    if (now == 0)return;
    res[edge[now].second] += 1;
    dfs(edge[now].first);
}
 
int main()
{
    scanf("%d %d %d %lld", &a, &b, &c, &k);
    dijkstra();
    dfs(k % c);
    ll sum = a * res[1] + b * res[2];
    res[3] = (k - sum) / c;
    printf("%lld %lld %lld\n", res[1], res[2], res[3]);
    return 0;
}

 

posted on 2020-04-02 19:20  Willems  阅读(150)  评论(0编辑  收藏  举报

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