题意
有 \(n\) 个工作,每个工作需要一些限制。
你可以花 \(s_i\) 的代价满足一个限制。
然后获得 \(h_i\) 的贡献。
问是的获得的贡献最大可以使多少?
Sol
最小割。
从源点往每个实验连 \(h_i\),每个实验往每个代价连 \(inf\).
代价往汇点连 \(s_i\) 就行了。
Code
#include <iostream>
#include <algorithm>
#include <cstdio>
#include <array>
#include <queue>
#include <vector>
#include <bitset>
#include <cstring>
#define int long long
#define pii pair <int, int>
using namespace std;
// #ifdef ONLINE_JUDGE
// #define getchar() (p1 == p2 && (p2 = (p1 = buf) + fread(buf, 1, 1 << 21, stdin), p1 == p2) ? EOF : *p1++)
// char buf[1 << 23], *p1 = buf, *p2 = buf, ubuf[1 << 23], *u = ubuf;
// #endif
int read() {
int p = 0, flg = 1;
char c = getchar();
while (c < '0' || c > '9') {
if (c == '-') flg = -1;
c = getchar();
}
while (c >= '0' && c <= '9') {
p = p * 10 + c - '0';
c = getchar();
}
return p * flg;
}
void write(int x) {
if (x < 0) {
x = -x;
putchar('-');
}
if (x > 9) {
write(x / 10);
}
putchar(x % 10 + '0');
}
#define fi first
#define se second
const int N = 1005, M = 10005, inf = 2e18;
namespace G {
array <int, N> fir;
array <int, M> nex, to, cap;
int cnt = 1;
void add(int x, int y, int z) {
cnt++;
nex[cnt] = fir[x];
to[cnt] = y;
cap[cnt] = z;
fir[x] = cnt;
}
void _add(int x, int y, int z) {
add(x, y, z);
add(y, x, 0);
}
}
namespace Mfl {
array <int, N> cur, dis;
queue <int> q;
bool bfs(pii st) {
dis.fill(-1), dis[st.fi] = 0;
q.push(st.fi);
while (!q.empty()) {
int u = q.front();
q.pop();
for (int i = G::fir[u]; i; i = G::nex[i]) {
if (!G::cap[i] || ~dis[G::to[i]]) continue;
dis[G::to[i]] = dis[u] + 1, q.push(G::to[i]);
}
}
return ~dis[st.se];
}
int dfs(int x, int augcd, pii st) {
if (x == st.se) return augcd;
int augc = augcd;
for (int &i = cur[x]; i; i = G::nex[i]) {
if (!G::cap[i] || dis[G::to[i]] <= dis[x]) continue;
int flow = dfs(G::to[i], min(augc, G::cap[i]), st);
augc -= flow;
G::cap[i] -= flow, G::cap[i ^ 1] += flow;
if (!augc) break;
}
return augcd - augc;
}
int dinic(pii st) {
int ans = 0;
while (bfs(st)) {
copy(G::fir.begin(), G::fir.end(), cur.begin());
ans += dfs(st.fi, inf, st);
}
return ans;
}
}
bitset <N> vis;
void dfs(int x) {
vis[x] = 1;
for (int i = G::fir[x]; i; i = G::nex[i]) {
if (!G::cap[i] || vis[G::to[i]]) continue;
dfs(G::to[i]);
}
}
char tools[10000];
signed main() {
int n, m; scanf("%d%d", &m, &n);
pii st = make_pair(n + m + 1, n + m + 2);
int ans = 0;
for (int i = 1; i <= m; i++) {
int x; scanf("%d", &x);
ans += x;
G::_add(st.fi, i + n, x);
memset(tools, 0, sizeof tools);
cin.getline(tools, 10000); int ulen = 0,tool;
while (sscanf(tools + ulen,"%d", &tool) == 1) {
G::_add(i + n, tool, inf);
if (tool == 0) ulen++;
else while (tool) tool /= 10, ulen++;
ulen++;
}
}
for (int i = 1; i <= n; i++) {
int x; scanf("%d", &x);
G::_add(i, st.se, x);
}
ans = ans - Mfl::dinic(st); dfs(st.fi);
for (int i = n + 1; i <= n + m; i++)
if (vis[i]) write(i - n), putchar(32);
puts("");
for (int i = 1; i <= n; i++)
if (vis[i]) write(i), putchar(32);
puts("");
write(ans), puts("");
return 0;
}
标签:fir,cnt,int,st,计划,P2762,include,太空飞行,dis
From: https://www.cnblogs.com/cxqghzj/p/17895290.html