UVA - 1627 Team them up!——二分图染色+01背包

这题不是普通的01背包模型，是一个判断可行空间的01背包，是uva323的缩水版

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
const int maxn = 110;
const int maxm = 220;
int g[maxn][maxn];
vector<int> G[maxn];
int vis[maxn];
int link_cnt;
vector<int> link[maxn];
int x[maxn], y[maxn], sub[maxn];
bool dp[maxn][maxm];
vector<int> path[maxn][maxm];

bool dfs(int u) {
    for (unsigned int i = 0; i < G[u].size(); i++) {
        int v = G[u][i];
        if (vis[v]) {
            if (vis[v] == -vis[u]) continue;
            else return false;
        }
        else {
            vis[v] = -vis[u];
            link[link_cnt].push_back(v);
            if (!dfs(v)) return false;
        }
    }
    return true;
}

int main() {
    int T; scanf("%d", &T);
    for (int kase = 1; kase <= T; kase++) {
        int n; scanf("%d", &n);
        memset(g, 0, sizeof(g));
        for (int i = 1; i <= n; i++) G[i].clear(), link[i].clear();
        for (int i = 1; i <= n; i++) {
            int x;
            while (~scanf("%d", &x) && x) g[i][x] = 1;
        }
        for (int i = 1; i <= n; i++) {
            for (int j = i + 1; j <= n; j++) {
                if (g[i][j] && g[j][i]) continue;
                G[i].push_back(j); G[j].push_back(i);
            }
        }
        memset(vis, 0, sizeof(vis));
        bool ok = true;
        link_cnt = 0;
        for (int i = 1; i <= n; i++) {
            if (vis[i]) continue;
            ++link_cnt;
            vis[i] = 1;
            link[link_cnt].push_back(i);
            if (!dfs(i)) { ok = false; break; }
        }
        if (ok) {
            memset(x, 0, sizeof(x));
            memset(y, 0, sizeof(y));
            for (int i = 1; i <= link_cnt; i++) {
                for (unsigned int j = 0; j < link[i].size(); j++) {
                    int t = link[i][j];
                    if (vis[t] == 1) x[i]++;
                    else if (vis[t] == -1) y[i]++;
                }
            }
            int m = link_cnt;
            for (int i = 1; i <= m; i++) sub[i] = x[i] - y[i];
            for (int i = 0; i <= m; i++) {
                for (int j = 0; j <= 205; j++) {
                    dp[i][j] = false;
                    path[i][j].clear();
                }
            }
            dp[0][100] = true;
            for (int i = 0; i <= m; i++) {
                for (int j = 0; j < 200; j++) {
                    if (!dp[i][j]) continue;
                    if (j + sub[i + 1] < 0 || j + sub[i + 1] > 200) continue;
                    if (j - sub[i + 1] < 0 || j - sub[i + 1] > 200) continue;
                    dp[i + 1][j + sub[i + 1]] = true;
                    path[i + 1][j + sub[i + 1]] = path[i][j];
                    path[i + 1][j + sub[i + 1]].push_back(1);
                    dp[i + 1][j - sub[i + 1]] = true;
                    path[i + 1][j - sub[i + 1]] = path[i][j];
                    path[i + 1][j - sub[i + 1]].push_back(-1);
                }
            }
            int pos = 0;
            for(; !dp[m][100+pos] && !dp[m][100-pos]; pos++);
            int state = dp[m][100+pos] ? 100+pos : 100-pos;
            int a[maxn], cnta = 0, b[maxn], cntb = 0;
            for (unsigned int i = 0; i < path[m][state].size(); i++) {
                int x = path[m][state][i];
                for (unsigned int j = 0; j < link[i + 1].size(); j++) {
                    int t = link[i+1][j];
                    if (x * vis[t] == 1) {
                        a[++cnta] = t;
                    }
                    else if (x * vis[t] == -1) {
                        b[++cntb] = t;
                    }
                }
            }
            //if (kase != 1) printf("\n");
            printf("%d", cnta);
            sort(a + 1, a + cnta + 1);
            for (int i = 1; i <= cnta; i++) printf(" %d", a[i]);
            printf("\n");
            sort(b + 1, b + cntb + 1);
            printf("%d", cntb);
            for (int i = 1; i <= cntb; i++) printf(" %d", b[i]);
            printf("\n");
        }
        else printf("No solution\n");
        cout << endl;
    }
    return 0;
}