_bzoj1070 [SCOI2007]修车【最小费用最大流】

传送门：http://www.lydsy.com/JudgeOnline/problem.php?id=1070

以后做网络流题目就是不能省内存。。。

#include <cstdio>
#include <cstring>
#include <algorithm>

const int maxnd = 10100, maxe = 100005;

int m, n, time[65][15], S, T;
int head[maxnd], next[maxe], from[maxe], to[maxe], w[maxe], cap[maxe], flow[maxe], lb;
int d[maxnd], p[maxnd], c[maxnd], que[maxnd], head_, tail, h;
char inq[maxnd];

inline void ist(int aa, int ss, int ww, int ca) {
to[lb] = ss;
from[lb] = aa;
next[lb] = head[aa];
head[aa] = lb;
w[lb] = ww;
cap[lb] = ca;
++lb;

to[lb] = aa;
from[lb] = ss;
next[lb] = head[ss];
head[ss] = lb;
w[lb] = -ww;
cap[lb] = 0;
++lb;
}
inline bool spfa(int & co) {
memset(d, 0x3c, sizeof d);
memset(inq, 0, sizeof inq);
head_ = tail = 0;
que[tail++] = S;
inq[S] = 1;
d[S] = 0;
c[S] = 2147483647;
while (head_ != tail) {
h = que[head_++];
inq[h] = 0;
if (head_ == T + 3) {
head_ = 0;
}
for (int j = head[h]; j != -1; j = next[j]) {
if (flow[j] < cap[j] && d[to[j]] > d[h] + w[j]) {
d[to[j]] = d[h] + w[j];
p[to[j]] = j;
c[to[j]] = std::min(c[h], cap[j] - flow[j]);
if (!inq[to[j]]) {
inq[to[j]] = 1;
que[tail++] = to[j];
if (tail == T + 3) {
tail = 0;
}
}
}
}
}
if (d[T] == 0x3c3c3c3c) {
return false;
}
co += d[T] * c[T];
for (int i = T; i != S; i = from[p[i]]) {
flow[p[i]] += c[T];
flow[p[i] ^ 1] -= c[T];
}
return true;
}
inline int mcmf(void) {
int co = 0;
while (spfa(co));
return co;
}

int main(void) {
//freopen("in.txt", "r", stdin);
memset(head, -1, sizeof head);
memset(next, -1, sizeof next);
scanf("%d%d", &m, &n);
T = n * (m + 1) + 1;
for (int i = 1; i <= n; ++i) {
ist(S, i, 0, 1);
for (int j = 1; j <= m; ++j) {
scanf("%d", time[i] + j);
}
}
for (int j = 1; j <= m; ++j) {
for (int k = 1; k <= n; ++k) {
for (int i = 1; i <= n; ++i) {
ist(i, j * n + k, time[i][j] * k, 1);
}
ist(j * n + k, T, 0, 1);
}
}
printf("%.2f\n", (double)mcmf() / (double)n);
return 0;
}