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QOJ
ID | 题目 | 提交者 | 结果 | 用时 | 内存 | 语言 | 文件大小 | 提交时间 | 测评时间 |
---|---|---|---|---|---|---|---|---|---|
#660008 | #7898. I Just Want... One More... | fosov | ML | 1ms | 5272kb | C++14 | 3.5kb | 2024-10-20 02:07:52 | 2024-10-20 02:07:52 |
Judging History
answer
#include "bits/stdc++.h"
using namespace std;
#define ll long long
#define MOD ((int) (1e9) + 7)
#define pii pair<int, int>
#define N 100010
#define inf 0x7fffffff
struct Edge {
int u, v, c, nxt;
Edge(): u(0), v(0), c(0), nxt(0) {};
Edge(int u, int v, int c, int nxt): u(u), v(v), c(c), nxt(nxt) {};
};
struct MaxFlow {
int n, m;
Edge E[N];
int h[N], cur[N], dis[N], flow;
int q[N], ql, qr;
bool inS[N], inT[N];
void init(int n) {
this->n = n;
this->m = 2;
for (int i = 1; i <= n; ++ i) h[i] = 0;
}
void add_edge(int u, int v, int c) {
E[m] = Edge(u, v, c, h[u]), h[u] = m ++;
E[m] = Edge(v, u, 0, h[v]), h[v] = m++;
}
bool bfs(int s, int t) {
for (int i = 1; i <= n; ++ i) dis[i] = inf;
ql = qr = 0;
q[qr ++] = s;
dis[s] = 0, cur[s] = h[s];
while (ql < qr) {
int u = q[ql ++];
for (int i = h[u]; i; i = E[i].nxt) {
auto [_, v, c, __] = E[i];
if (c && dis[v] == inf) {
dis[v] = dis[u] + 1;
cur[v] = h[v];
q[qr ++] = v;
}
}
}
return dis[t] != inf;
}
int dfs(int u, int t, int in) {
if (u == t) return in;
if (dis[u] >= dis[t]) return 0;
int out = 0;
for (int i = cur[u]; i && in > out; i = E[i].nxt) {
cur[u] = i;
auto [_, v, c, __] = E[i];
int vout = dfs(v, t, min(in - out, c));
E[i].c -= vout, E[i^1].c += vout, out += vout;
}
return out;
}
void go(int s, int t) {
flow = 0;
int sflow;
while (bfs(s, t)) while (sflow = dfs(s, t, inf)) flow += sflow;
}
void revisit(int s, int t) {
for (int i = 1; i <= n; ++ i) inS[i] = inT[i] = 0;
ql = qr = 0;
q[qr ++] = s;
inS[s] = 1;
while (ql < qr) {
int u = q[ql ++];
for (int i = h[u]; i; i = E[i].nxt) {
auto [_, v, c, __] = E[i];
if (c && !inS[v]) {
q[qr ++] = v;
inS[v] = 1;
}
}
}
ql = qr = 0;
q[qr ++] = t;
inT[t] = 1;
while (ql < qr) {
int u = q[ql ++];
for (int i = h[u]; i; i = E[i].nxt) {
auto [v, _, c, __] = E[i^1];
if (c && !inT[v]) {
q[qr ++] = v;
inT[v] = 1;
}
}
}
}
} mf;
int main() {
#ifdef TEST
freopen("zz.in", "r+", stdin);
#endif
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int t; cin >> t;
while (t --) {
int n, m; cin >> n >> m;
int s = 2*n+1, t = s+1;
mf.init(t);
for (int i = 1; i <= n; ++ i) mf.add_edge(s, i, 1);
for (int i = n+1; i <= 2*n; ++ i) mf.add_edge(i, t, 1);
for (int i = 0; i < m; ++ i) {
int u, v; cin >> u >> v; v += n;
mf.add_edge(u, v, 1);
}
mf.go(s, t);
mf.revisit(s, t);
int Us = 0, Vs = 0;
for (int i = 1; i <= n; ++ i) Us += mf.inS[i];
for (int i = n+1; i <= 2*n; ++ i) Vs += mf.inT[i];
cout << 1ll * Us * Vs << '\n';
}
return 0;
}
詳細信息
Test #1:
score: 100
Accepted
time: 1ms
memory: 5272kb
input:
3 4 3 1 2 3 2 4 3 3 3 1 3 2 2 3 1 3 2 1 2 1 2
output:
6 0 4
result:
ok 3 number(s): "6 0 4"
Test #2:
score: -100
Memory Limit Exceeded
input:
10000 5 4 2 2 3 1 5 3 1 1 1 1 1 1 1 1 1 1 2 2 2 2 1 2 1 1 1 1 1 1 1 1 1 1 1 1 2 3 2 1 1 2 1 1 5 5 1 4 2 2 3 1 1 3 1 2 2 4 2 2 2 1 1 2 1 1 5 1 5 3 3 1 2 2 1 1 1 1 3 2 3 1 2 1 5 2 1 2 2 3 5 3 1 5 4 2 1 2 4 1 1 1 2 3 1 1 2 2 2 1 4 1 1 4 3 1 1 1 1 1 1 1 2 1 2 2 3 3 1 3 2 3 2 2 3 3 1 3 3 3 1 2 3 3 2 2 1 ...