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#641688#7612. Matrix InversepropaneWA 693ms112768kbC++204.9kb2024-10-14 22:20:232024-10-14 22:20:24

Judging History

你现在查看的是最新测评结果

  • [2024-10-14 22:20:24]
  • 评测
  • 测评结果:WA
  • 用时:693ms
  • 内存:112768kb
  • [2024-10-14 22:20:23]
  • 提交

answer

#include<iostream>
#include<cstring>
#include<vector>
#include<random>
#include<numeric>
#include<array>
#include<algorithm>
using namespace std;
using LL = long long;
const int mod = 1e9 + 7;
void add(int &a, int b){
    a += b;
    if (a >= mod) a -= mod;
}

void sub(int &a, int b){
    a -= b;
    if (a < 0) a += mod;
}

int mul(int a, int b){
    return 1LL * a * b % mod;
}

int qpow(int a, int b){
    int ans = 1;
    while(b){
        if (b & 1) ans = mul(ans, a);
        b >>= 1;
        a = mul(a, a);
    }
    return ans;
}

int main(){

#ifdef LOCAL
    freopen("data.in", "r", stdin);
    freopen("data.out", "w", stdout);
#endif

    cin.tie(0);
    cout.tie(0);
    ios::sync_with_stdio(0);

    mt19937 rnd(213423421);
    int n;
    cin >> n;
    vector<vector<int> > a(n, vector<int>(n));
    for(int i = 0; i < n; i++){
        for(int j = 0; j < n; j++){
            cin >> a[i][j];
        }
    }
    vector<vector<int> > b(n, vector<int>(n));
    for(int i = 0; i < n; i++){
        for(int j = 0; j < n; j++){
            cin >> b[i][j];
        }
    }

    uniform_int_distribution<int> dist(1, mod - 1);
    vector<int> row, col;

    if (n <= 12){
        for(int i = 0; i < n; i++){
            row.push_back(i);
            col.push_back(i);
        }
    }
    else{
        {
            vector<int> v(n);
            for(int i = 0; i < n; i++){
                v[i] = dist(rnd);
            }
            auto bk = v;
            {
                vector<int> nv(n);
                for(int i = 0; i < n; i++){
                    for(int j = 0; j < n; j++){
                        add(nv[j], mul(v[i], a[i][j]));
                    }
                }
                v.swap(nv);
            }
            {
                vector<int> nv(n);
                for(int i = 0; i < n; i++){
                    for(int j = 0; j < n; j++){
                        add(nv[j], mul(v[i], b[i][j]));
                    }
                }
                v.swap(nv);
            }
            for(int i = 0; i < n; i++){
                if (bk[i] != v[i]){
                    row.push_back(i);
                }
            }
        }
        {
            vector<int> v(n);
            for(int i = 0; i < n; i++){
                v[i] = dist(rnd);
            }
            auto bk = v;
            {
                vector<int> nv(n);
                for(int i = 0; i < n; i++){
                    for(int j = 0; j < n; j++){
                        add(nv[j], mul(v[i], b[i][j]));
                    }
                }
                v.swap(nv);
            }
            {
                vector<int> nv(n);
                for(int i = 0; i < n; i++){
                    for(int j = 0; j < n; j++){
                        add(nv[j], mul(v[i], a[i][j]));
                    }
                }
                v.swap(nv);
            }
            for(int i = 0; i < n; i++){
                if (bk[i] != v[i]){
                    col.push_back(i);
                }
            }
        }
    }

    auto guass = [&](vector<vector<int> > &a){
        const int n = a.size();
        for(int i = 0; i < n; i++){
            int t = -1;
            for(int j = i; j < n; j++){
                if (a[j][i]){
                    t = j;
                    break;
                }
            }
            swap(a[t], a[i]);
            int inv = qpow(a[i][i], mod - 2);
            for(int j = 0; j < n + 1; j++) a[i][j] = mul(a[i][j], inv);
            for(int j = 0; j < n; j++){
                if (i != j and a[j][i]){
                    for(int k = n; k >= i; k--){
                        sub(a[j][k], mul(a[j][i], a[i][k]));
                    }
                }
            }
        }
        vector<int> ans(n);
        for(int i = 0; i < n; i++) ans[i] = a[i].back();
        return ans;
    };

    vector<pair<int, int> > p;
    vector<vector<int> > q(n, vector<int>(n, -1));

    for(auto x : row){
        for(auto y : col){
            q[x][y] = p.size();
            p.push_back({x, y});
        }
    }

    vector<vector<int> > c(p.size(), vector<int>(p.size() + 1));

    for(int l = 0; l < p.size(); l++){
        auto [x, y] = p[l];
        c[l].back() = (x == y);
        for(int i = 0; i < n; i++){
            if (q[i][y] == -1){
                sub(c[l].back(), mul(a[x][i], b[i][y]));
            }
            else{
                c[l][q[i][y]] = a[x][i];
            }
        }
    }

    auto res = guass(c);

    vector<array<int, 3> > ans;
    for(int i = 0; i < p.size(); i++){
        auto [x, y] = p[i];
        if (res[i] != b[x][y]){
            ans.push_back({x, y, res[i]});
        }
    }
    cout << ans.size() << '\n';
    for(auto [x, y, z] : ans) cout << x + 1 << ' ' << y + 1 << ' ' << z << '\n';

}

詳細信息

Test #1:

score: 100
Accepted
time: 0ms
memory: 3608kb

input:

1
953176428
107682094

output:

0

result:

ok single line: '0'

Test #2:

score: -100
Wrong Answer
time: 693ms
memory: 112768kb

input:

1995
586309310 548144807 578573993 437893403 641164340 712256053 172321263 108058526 768610920 123320669 762746291 856047593 979279376 29067913 309867338 292286426 45124325 239705174 675003623 213743652 620561338 116308277 695369179 669459894 682522334 846995555 159510341 999359657 645579085 7499563...

output:

4
238 238 426153420
238 499 703395553
499 238 604559761
499 499 904951262

result:

wrong answer 1st lines differ - expected: '2', found: '4'