Sem_2_Task_1

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

struct Edge;

const size_t INF = size_t(1e12);

namespace {
    using NumsVec = std::vector<size_t>;
    using VecNumsVec = std::vector<NumsVec>;
    using BoolVec = std::vector<bool>;
    using EdgeVec = std::vector<Edge>;
    using VecEdgeVec = std::vector<EdgeVec>;
}

struct Edge {
    Edge() = default;
    Edge(std::pair<size_t, size_t> edge) : from(edge.first), to(edge.second) {};
    Edge(size_t i, size_t j, size_t w) : from(i), to(j), w(w) {};

    bool operator==(const Edge& other) const {
        return from == other.from && to == other.to;
    }

    size_t from = 0;
    size_t to = 0;
    size_t w = 0;
};

std::istream& operator>>(std::istream& input, Edge& p) {
    input >> p.from >> p.to >> p.w;
    --p.from;
    --p.to;
    return input;
}

void InputEdges(std::vector<Edge>& edges) {
    for (auto& edge : edges) {
        std::cin >> edge;
    }
}

template<>
struct std::hash<Edge> {
    size_t operator()(const Edge& p) const {
        return p.from * p.to;
    }
};

std::ostream& operator<<(std::ostream& output, NumsVec& vec) {
    for (auto elem : vec) {
        std::cout << elem + 1 << " ";
    }
    return output;
}

struct Graph {
    Graph(size_t n) : size(n), neighbours(n), visited(n, false), color(n, 0),
    top_sort(n, 0), top_sort_pos(n - 1), d(n, INF) {};

    Graph(size_t n, VecNumsVec& matrix) : size(n), visited(n, false), color(n, 0),
    top_sort(n, 0), top_sort_pos(n - 1), d(n, INF), neighbours(n) {
        for (size_t v = 0; v < n; ++v) {
            for (size_t u = 0; u < n; ++u) {
                sum_w += matrix[v][u];
                if (matrix[v][u] != 0 || v == u) {
                    neighbours[v].push_back(Edge(v, u, matrix[v][u]));
                }
            }
        }
    };

    size_t size = 0;
    bool cycle = false;

    std::vector<EdgeVec> neighbours;
    BoolVec visited;
    NumsVec color;
    NumsVec top_sort;
    NumsVec d;
    size_t sum_w = 0;
    size_t top_sort_pos = 0;
};

int64_t Dijkstra(Graph& g, size_t s, size_t f) {
    g.d[s] = 0;
    std::set<std::pair<size_t, size_t>> vert;
    vert.insert({g.d[s], s});
    while (!vert.empty()) {
        size_t v = vert.begin()->second;
        vert.erase(vert.begin());
        for (auto edge : g.neighbours[v]) {
            if (g.d[edge.to] > g.d[v] + edge.w) {
                vert.erase({g.d[edge.to], edge.to});
                g.d[edge.to] = g.d[v] + edge.w;
                vert.insert({g.d[edge.to], edge.to});
            }
        }
    }
    if (g.d[f] == INF) {
        return g.sum_w;
    }
    return g.d[f];
}

int main() {
    size_t n;
    std::cin >> n;
    VecNumsVec matr(n, NumsVec(n, 0));
    for (size_t i = 0; i < n; ++i) {
        for (size_t j = 0; j < n; ++j) {
            std::cin >> matr[i][j];
        }
    }
    Graph g(n, matr);
    int64_t cheapest_way = Dijkstra(g, 0, 1);
    std::cout << g.sum_w - cheapest_way;
}