标签:int start algorithm return str include turn ons [1] php
传送门:http://www.lydsy.com/JudgeOnline/problem.php?id=1003
预处理出第i天到第j天走一条航线时的最短路。
#include <cstdio>
#include <cstring>
#include <algorithm>
const int maxn = 105, maxm = 25, maxe = 1005;
int n, m, K, e, t1, t2, t3, dd;
int head[maxm], to[maxe << 1], next[maxe << 1], w[maxe << 1], lb;
int p[10005], a[10005], b[10005];
char book[maxm], inq[maxm];
int que[maxm], head_, tail, h, d[maxm], price[maxn][maxn];
int f[maxn];
inline void ist(int aa, int ss, int ww) {
to[lb] = ss;
next[lb] = head[aa];
head[aa] = lb;
w[lb] = ww;
++lb;
}
inline void spfa(int start, int end) {
memset(book, 0, sizeof book);
for (int i = 0; i < dd; ++i) {
if (a[i] <= end && b[i] >= start) {
book[p[i]] = 1;
}
}
if (book[1] || book[m]) {
price[start][end] = 0x3c3c3c3c;
return;
}
memset(que, 0, sizeof que);
memset(d, 0x3c, sizeof d);
memset(inq, 0, sizeof inq);
head_ = tail = 0;
que[tail++] = 1;
inq[1] = true;
d[1] = 0;
while (head_ != tail) {
h = que[head_++];
inq[h] = 0;
if (head_ == m) {
head_ = 0;
}
for (int j = head[h]; j != -1; j = next[j]) {
if (!book[to[j]] && d[to[j]] > d[h] + w[j]) {
d[to[j]] = d[h] + w[j];
if (!inq[to[j]]) {
inq[to[j]] = 1;
que[tail++] = to[j];
if (tail == m) {
tail = 0;
}
}
}
}
}
price[start][end] = d[m];
}
int main(void) {
//freopen("in.txt", "r", stdin);
memset(next, -1, sizeof next);
memset(head, -1, sizeof head);
scanf("%d%d%d%d", &n, &m, &K, &e);
while (e--) {
scanf("%d%d%d", &t1, &t2, &t3);
ist(t1, t2, t3);
ist(t2, t1, t3);
}
scanf("%d", &dd);
for (int i = 0; i < dd; ++i) {
scanf("%d%d%d", p + i, a + i, b + i);
}
for (int i = 1; i <= n; ++i) {
for (int j = i; j <= n; ++j) {
spfa(i, j);
}
}
f[0] = -K;
for (int i = 1; i <= n; ++i) {
f[i] = 2147483647;
for (int j = 0; j < i; ++j) {
if (price[j + 1][i] < 0x3c3c3c3c) {
f[i] = std::min(f[i], f[j] + price[j + 1][i] * (i - j));
}
}
f[i] += K;
}
printf("%d\n", f[n]);
return 0;
}
标签:int start algorithm return str include turn ons [1] php
原文地址:http://www.cnblogs.com/ciao-sora/p/6165862.html