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QOJ

IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#497893#7671. Metal Processing PlantMax_s_xaMWA 1ms5788kbC++146.1kb2024-07-29 20:07:102024-07-29 20:07:12

Judging History

你现在查看的是最新测评结果

  • [2024-07-29 20:07:12]
  • 评测
  • 测评结果:WA
  • 用时:1ms
  • 内存:5788kb
  • [2024-07-29 20:07:10]
  • 提交

answer

#include <iostream>
#include <algorithm>
#include <vector>

typedef long long ll;
typedef double lf;

// #define DEBUG 1
struct IO
{
    #define MAXSIZE (1 << 20)
    #define isdigit(x) (x >= '0' && x <= '9')
    char buf[MAXSIZE], *p1, *p2;
    char pbuf[MAXSIZE], *pp;
    #if DEBUG
    #else
    IO() : p1(buf), p2(buf), pp(pbuf) {}
    ~IO() {fwrite(pbuf, 1, pp - pbuf, stdout);}
    #endif
    #define gc() (p1 == p2 && (p2 = (p1 = buf) + fread(buf, 1, MAXSIZE, stdin), p1 == p2) ? ' ' : *p1++)
    #define blank(x) (x == ' ' || x == '\n' || x == '\r' || x == '\t')

    template <typename T>
    void Read(T &x)
    {
        #if DEBUG
        std::cin >> x;
        #else
        bool sign = 0; char ch = gc(); x = 0;
        for (; !isdigit(ch); ch = gc())
            if (ch == '-') sign = 1;
        for (; isdigit(ch); ch = gc()) x = x * 10 + (ch ^ 48);
        if (sign) x = -x;
        #endif
    }
    void Read(char *s)
    {
        #if DEBUG
        std::cin >> s;
        #else
        char ch = gc();
        for (; blank(ch); ch = gc());
        for (; !blank(ch); ch = gc()) *s++ = ch;
        *s = 0;
        #endif
    }
    void Read(char &c) {for (c = gc(); blank(c); c = gc());}

    void Push(const char &c)
    {
        #if DEBUG
        putchar(c);
        #else
        if (pp - pbuf == MAXSIZE) fwrite(pbuf, 1, MAXSIZE, stdout), pp = pbuf;
        *pp++ = c;
        #endif
    }
    template <typename T>
    void Write(T x)
    {
        if (x < 0) x = -x, Push('-');
        static T sta[35];
        int top = 0;
        do sta[top++] = x % 10, x /= 10; while (x);
        while (top) Push(sta[--top] ^ 48);
    }
    template <typename T>
    void Write(T x, char lst) {Write(x), Push(lst);}
} IO;
#define Read(x) IO.Read(x)
#define Write(x, y) IO.Write(x, y)
#define Put(x) IO.Push(x)

using namespace std;

const int MAXN = 210;

int n, d[MAXN][MAXN], ans;

struct Edge
{
    int u, v, w;
    bool operator < (const Edge u) const { return w > u.w; }
};
vector <Edge> e;

int fa[MAXN], col[MAXN]; bool vis[MAXN];
int Find(int x) { return x == fa[x] ? x : fa[x] = Find(fa[x]); }
inline void Union(int u, int v) { u = Find(u), v = Find(v); if (u != v) fa[u] = v; }

int st[MAXN], top;
vector <int> g[MAXN << 1];

int dfn[MAXN << 1], low[MAXN << 1], bel[MAXN << 1], scc, clk;
int stk[MAXN << 1], tot; bool inq[MAXN << 1];
inline void Tarjan(int u)
{
    dfn[u] = low[u] = ++clk, stk[++tot] = u, inq[u] = 1;
    for (auto v : g[u])
        if (!dfn[v]) Tarjan(v), low[u] = min(low[u], low[v]);
        else if (inq[v]) low[u] = min(low[u], dfn[v]);
    if (low[u] == dfn[u])
    {
        scc++;
        while (stk[tot] != u) bel[stk[tot]] = scc, inq[stk[tot]] = 0, tot--;
        bel[u] = scc, inq[u] = 0, tot--;
    }
}
inline bool Check()
{
    for (int i = 1; i <= 2 * n; i++)
    {
        dfn[i] = low[i] = bel[i] = inq[i] = 0;
        // cout << i << ": ";
        // for (auto v : g[i]) cout << v << ' '; cout << '\n';
    }
    scc = clk = tot = 0;
    for (int i = 1; i <= 2 * n; i++)
        if (!dfn[i]) Tarjan(i);
    for (int i = 1; i <= n; i++)
        if (bel[i] == bel[i + n]) return 0;
    return 1;
}

inline void Solve(int bg)
{
    // cout << "Solve " << bg << "\n";
    // for (int i = 0; i < bg; i++) cout << e[i].u << ' ' << e[i].v << " " << e[i].w << '\n';
    // for (int i = 1; i <= n; i++) cout << col[i] << ' '; cout << '\n';
    top = 0;
    for (int i = 1; i <= n; i++) g[i].clear(), g[i + n].clear();
    for (int i = 1; i <= n; i++)
        if (vis[i] && fa[i] == i) st[++top] = i;
    int l = bg, r = e.size() - 1, mid;
    while (l <= r)
    {
        mid = l + r >> 1;
        for (int i = 1; i <= n; i++) g[i].clear(), g[i + n].clear();
        int x = Find(e[bg - 1].u), y = col[e[bg - 1].u];
        if (vis[x]) g[x + (y ? 0 : n)].push_back(x + (y ? n : 0));
        x = Find(e[bg - 1].v), y = col[e[bg - 1].v];
        if (vis[x]) g[x + (y ? 0 : n)].push_back(x + (y ? n : 0));
        for (int i = bg; i <= mid; i++)
        {
            int u = e[i].u, v = e[i].v, w = e[i].w;
            if (Find(u) == Find(v))
            {
                // cout << u << ' ' << v << " ##\n";
                if (col[u] != col[v]) continue;
                u = Find(u);
                g[u + (col[u] ? 0 : n)].push_back(u + (col[u] ? n : 0));
                continue;
            }
            if (!vis[u] || !vis[v]) continue;
            x = col[u], y = col[v], u = Find(u), v = Find(v);
            g[u + (x ? n : 0)].push_back(v + (y ? 0 : n));
            g[v + (y ? n : 0)].push_back(u + (x ? 0 : n));
        }
        // cout << "check " << mid << "\n";
        if (Check()) l = mid + 1;
        else r = mid - 1;
    }
    // cout << l << "\n";
    if (l == e.size()) ans = min(ans, e[bg - 1].w);
    else ans = min(ans, e[bg - 1].w + e[l].w);
}

int main()
{
    // freopen("A.in", "r", stdin);
    // freopen("A.out", "w", stdout);
    #if DEBUG
    #else
    ios::sync_with_stdio(0), cin.tie(0);
    #endif
    Read(n);
    for (int i = 1; i <= n; i++)
        for (int j = i + 1; j <= n; j++)
            Read(d[i][j]), d[j][i] = d[i][j], e.push_back(Edge{i, j, d[i][j]});
    if (n == 1) return cout << "0\n", 0;
    sort(e.begin(), e.end());
    // for (int i = 0; i < e.size(); i++) cout << e[i].u << ' ' << e[i].v << " " << e[i].w << '\n';
    
    ans = e[0].w;
    for (int i = 1; i <= n; i++) fa[i] = i;
    for (int _ = 0; _ < e.size(); _++)
    {
        int u = e[_].u, v = e[_].v;
        if (Find(u) == Find(v))
        {
            if (col[u] == col[v]) { Solve(_ + 1); break; }
            continue;
        }
        vis[u] = vis[v] = 1;
        Solve(_ + 1);
        if (col[u] == col[v])
        {
            for (int i = 1; i <= n; i++)
                if (Find(i) == Find(v)) col[i] ^= 1;
        }
        Union(u, v);
        // cout << "add " << u << ' ' << v << '\n';
        // for (int i = 1; i <= n; i++) cout << col[i] << ' '; cout << '\n';
    }
    cout << ans << '\n';
    return 0;
}

Details

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Test #1:

score: 100
Accepted
time: 1ms
memory: 5704kb

input:

5
4 5 0 2
1 3 7
2 0
4

output:

4

result:

ok single line: '4'

Test #2:

score: 0
Accepted
time: 0ms
memory: 3728kb

input:

7
1 10 5 5 5 5
5 10 5 5 5
100 100 5 5
10 5 5
98 99
3

output:

15

result:

ok single line: '15'

Test #3:

score: 0
Accepted
time: 0ms
memory: 3652kb

input:

1

output:

0

result:

ok single line: '0'

Test #4:

score: -100
Wrong Answer
time: 1ms
memory: 5788kb

input:

2
1

output:

1

result:

wrong answer 1st lines differ - expected: '0', found: '1'