[网络流24题] P3254 圆桌问题

#include <bits/stdc++.h>
#define endl '\n'
#define IOS                  \
    ios::sync_with_stdio(0); \
    cin.tie(0);              \
    cout.tie(0)
#define P pair<int, int>
typedef long long ll;
using namespace std;

const int N = 150 + 270 + 5;
const int M = N * N;
const int INF = 0x3f3f3f3f;

struct edge {
    int v, w, to;
} e[M * 2];
int pre[N], cnt_edge, dep[N];
int S, T, z, head[N], sum;
int n, m, q[N], cur[N];
void add(int u, int v, int w) {
    // cout << "add: " << u << " " << v << endl;
    e[cnt_edge] = {v, w, head[u]};
    head[u] = cnt_edge++;
    e[cnt_edge] = {u, 0, head[v]};
    head[v] = cnt_edge++;
}
bool bfs() {
    for (int i = 0; i <= T; i++) dep[i] = 0;
    dep[S] = 1;
    int l = 0, r = 1;
    q[r] = S;
    while (l < r) {
        int u = q[++l];
        for (int i = head[u]; i != -1; i = e[i].to) {
            int v = e[i].v;
            if (!dep[v] && e[i].w) dep[v] = dep[u] + 1, q[++r] = v;
        }
    }
    return dep[T];
}
int dfs(int u, int mi) {
    int res = 0;
    if (mi == 0 || u == T) return mi;
    for (int &i = cur[u]; i != -1; i = e[i].to) {
        int v = e[i].v;
        if (dep[u] + 1 == dep[v] && e[i].w) {
            int minn = dfs(v, min(mi - res, e[i].w));
            e[i].w -= minn;
            e[i ^ 1].w += minn;
            res += minn;
            if (res == mi) return res;
        }
    }
    if (res == 0) dep[u] = 0;
    return res;
}
int dinic() {
    ll res = 0;
    while (bfs()) {
        memcpy(cur, head, sizeof(head));
        //    cout<<res<<endl;
        res += dfs(S, INF);
    }
    // cout << res << endl;
    return res;
}
int c[150 + 5], vis[150 + 5];
int id(int x, int day) { return x + day * n; }

int main() {
    memset(head, -1, sizeof head);
    cin >> n >> m;
    S = n + m + 1, T = S + 1;
    int sum = 0;
    for (int i = 1; i <= n; i++) {
        cin >> c[i];
        sum += c[i];
        add(S, id(i, 0), c[i]);
        for (int j = 1; j <= m; j++) {
            add(id(i, 0), id(j, 1), 1);
        }
    }

    for (int i = 1, c; i <= m; i++) {
        cin >> c;
        add(id(i, 1), T, c);
    }
    int ans = dinic() == sum ? 1 : 0;
    cout << ans << endl;
    if(ans){
    for (int i = 1; i <= n; i++) {
        for (int j = head[id(i, 0)]; ~j; j = e[j].to) {
            if(e[j^1].w != 0){
                cout << e[j].v -n << " ";
                e[j].w += 1;
                e[j ^ 1].w -= 1;
            }
        }
        cout << endl;
    }
    }
    return 0;
}