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P276 软件补丁问题

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P276 软件补丁问题

题面

题目链接

解法

这题不是网络流！

状压+最短路即可。

AC代码

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/**
 * @file:           P2761.cpp
 * @author:         yaoxi-std
 * @url:            https://www.luogu.com.cn/problem/P2761
*/
// #pragma GCC optimize ("O2")
// #pragma GCC optimize ("Ofast", "inline", "-ffast-math")
// #pragma GCC target ("avx,sse2,sse3,sse4,mmx")
#include <bits/stdc++.h>
using namespace std;
#define int long long
#define resetIO(x) \
    freopen(#x ".in", "r", stdin), freopen(#x ".out", "w", stdout)
#define debug(fmt, ...) \
    fprintf(stderr, "[%s:%d] " fmt "\n", __FILE__, __LINE__, ##__VA_ARGS__)
template <class _Tp>
inline _Tp& read(_Tp &x) {
    bool sign = false;
    char ch = getchar();
    long double tmp = 1;
    for (; !isdigit(ch); ch = getchar())
        sign |= (ch == '-');
    for (x = 0; isdigit(ch); ch = getchar())
        x = x * 10 + (ch ^ 48);
    if (ch == '.')
        for (ch = getchar(); isdigit(ch); ch = getchar())
            tmp /= 10.0, x += tmp * (ch ^ 48);
    return sign ? (x = -x) : x;
}
template <class _Tp>
inline void write(_Tp x) {
    if (x < 0)
        putchar('-'), x = -x;
    if (x > 9)
        write(x / 10);
    putchar((x % 10) ^ 48);
}
const int MAXN = 200;
const int MAXM = 1 << 20;
const int INF = 0x3f3f3f3f3f3f3f3f;
struct node {
    int u, dis;
    bool operator<(const node &o) const {
        return dis > o.dis;
    }
};
struct bugfix {
    int c, b1, b2, f1, f2;
};
int n, m, dis[MAXM];
bugfix g[MAXN];
char buf[MAXN];
priority_queue<node> que;
signed main() {
    read(n), read(m);
    for (int i = 1; i <= m; ++i) {
        read(g[i].c);
        scanf("%s", buf);
        for (int j = 0; j < n; ++j) {
            if (buf[j] == '+')
                g[i].b1 |= (1 << j);
            if (buf[j] == '-')
                g[i].b2 |= (1 << j);
        }
        scanf("%s", buf);
        for (int j = 0; j < n; ++j) {
            if (buf[j] == '-')
                g[i].f1 |= (1 << j);
            if (buf[j] == '+')
                g[i].f2 |= (1 << j);
        }
    }
    memset(dis, 0x3f, sizeof(dis));
    dis[(1 << n) - 1] = 0;
    que.push({(1 << n) - 1, 0ll});
    while (!que.empty()) {
        node t = que.top();
        que.pop();
        if (dis[t.u] < t.dis)
            continue;
        int u = t.u, d = t.dis;
        for (int i = 1; i <= m; ++i) {
            bugfix& b = g[i];
            if ((u & b.b1) == b.b1 && (u & b.b2) == 0) {
                int v = (u & (~b.f1)) | b.f2;
                if (dis[v] > dis[u] + b.c) {
                    dis[v] = dis[u] + b.c;
                    que.push({v, dis[v]});
                }
            }
        }
    }
    if (dis[0] == INF)
        puts("0");
    else
        write(dis[0]), putchar('\n');
    return 0;
}