Luogu SP839 OPTM - Optimal Marks(按位最小割)

这道题和 BZOJ 2400 是一道题,不多讲了

CODE

#include <cstdio>
#include <cstring>
#include <vector>
#include <queue>
#include <algorithm>
using namespace std;
typedef long long LL;
template<typename T>inline void read(T &num) {
    char ch; int flg=1;
    while((ch=getchar())<'0'||ch>'9')if(ch=='-')flg=-flg;
    for(num=0;ch>='0'&&ch<='9';num=num*10+ch-'0',ch=getchar());
    num*=flg;
}
const int inf = 1e9;
const int MAXN = 505;
const int MAXM = 30005;
int n, m, fir[MAXN], S, T, cnt;
struct edge { int to, nxt; int c; }e[MAXM];
inline void add(int u, int v, int cc, int rc=0) {
    e[cnt] = (edge){ v, fir[u], cc }; fir[u] = cnt++;
    e[cnt] = (edge){ u, fir[v], rc }; fir[v] = cnt++;
}
int dis[MAXN], vis[MAXN], info[MAXN], cur, q[MAXN];
inline bool bfs() {
    int head = 0, tail = 0;
    vis[S] = ++cur; q[tail++] = S;
    while(head < tail) {
        int u = q[head++];
        for(int i = fir[u]; ~i; i = e[i].nxt)
            if(e[i].c && vis[e[i].to] != cur)
                vis[e[i].to] = cur, dis[e[i].to] = dis[u] + 1, q[tail++] = e[i].to;
    }
    if(vis[T] == cur) memcpy(info, fir, (T+1)<<2);
    return vis[T] == cur;
}
int dfs(int u, int Max) {
    if(u == T || !Max) return Max;
    int flow=0, delta;
    for(int &i = info[u]; ~i; i = e[i].nxt)
        if(e[i].c && dis[e[i].to] == dis[u] + 1 && (delta=dfs(e[i].to, min(e[i].c, Max-flow)))) {
            e[i].c -= delta, e[i^1].c += delta, flow += delta;
            if(flow == Max) return flow;
        }
    return flow;
}
inline int dinic() {
    memset(vis, 0, sizeof vis);
    int flow=0, x;
    while(bfs()) {
        while((x=dfs(S, inf))) flow+=x;
    }
    return flow;
}
int A[MAXN], X[3005], Y[3005], ans[MAXN];
bool flg[MAXN];
void Getans(int u, int val) {
    ans[u] += val; flg[u] = 1;
    for(int i = fir[u]; ~i; i = e[i].nxt)
        if(e[i].c && !flg[e[i].to])
            Getans(e[i].to, val);
}
int main () {
    int kase;
    read(kase);
    while(kase--) {
        read(n); read(m); S = 0, T = n+1;
        memset(A, -1, sizeof A);
        for(int i = 1; i <= m; ++i) read(X[i]), read(Y[i]);
        int tot, x, y;
        read(tot); while(tot--) read(x), read(y), A[x] = y;
        for(int bit = 0; bit < 31; ++bit) {
            memset(fir, -1, sizeof fir); cnt = 0;
            for(int i = 1; i <= m; ++i) add(X[i], Y[i], 1, 1);
            for(int i = 1; i <= n; ++i) {
                if(A[i] < 0) continue;
                if(A[i]&(1<<bit)) add(S, i, inf);
                else add(i, T, inf);
            }
            memset(flg, 0, sizeof flg);
            dinic(); Getans(S, 1<<bit);
        }
        for(int i = 1; i <= n; ++i)
            printf("%d\n", ans[i]), ans[i] = 0;
    }
}