Go: package main

import (
	"fmt"
	"sort"
)

type Edge struct {
	I int
	J int
	A int
}

func main() {
	var n int
	fmt.Scan(&n)

	g := make([][]int, n)
	edges := make([]Edge, 0, n*(n-1)/2)
	parents := make([]int, n)
	for i := 0; i < n; i++ {
		g[i] = make([]int, n)
		for j := 0; j < n; j++ {
			fmt.Scan(&g[i][j])
			if g[i][j] >= 0 {
				edges = append(edges, Edge{i, j, g[i][j]})
			}
		}
		parents[i] = i
	}
	sort.SliceStable(edges, func(i, j int) bool { return edges[i].A >= edges[j].A })

	sum := 0
	num := 0
	for len(edges) > 0 && num < n-1 {
		edge := edges[len(edges)-1]
		edges = edges[:len(edges)-1]

		if same(edge.I, edge.J, &parents) {
			continue
		}
		union(edge.I, edge.J, &parents)
		sum += edge.A
		num += 1
	}
	fmt.Println(sum)
}



func root(id int, parents *[]int) int {
	if id == (*parents)[id] {
		return id
	}
	return root((*parents)[id], parents)
}

func union(i, j int, parents *[]int) {
	(*parents)[root(j, parents)] = (*parents)[root(i, parents)]
}

func same(i, j int, parents *[]int) bool {
	return root(i, parents) == root(j, parents)
}

C++: /**
 * @copyright (c) 2020 Daisuke Hashimoto
 */

#include <algorithm>
#include <cstdint>
#include <functional>
#include <iostream>
#include <queue>
#include <string>
#include <utility>
#include <vector>

constexpr int32_t kMaxNumberOfVertices = 100;
constexpr int32_t kInvalidIndex = -1;

void CallPrimAlgorithm(std::istream &input_stream);

struct Edge {
  int32_t to{kInvalidIndex};
  int32_t weight{INT32_MAX};
};

struct Vertex {
  bool assigned_to_tree{false};
  std::vector<Edge> neighbours;
};

class PrimAlgorithm {
 public:
  PrimAlgorithm() noexcept;
  ~PrimAlgorithm() noexcept;
  void SetNumberOfVertices(const int32_t number_of_vertices) noexcept;
  void AddVertex(const int32_t from, const int32_t to, const int32_t weight) noexcept;
  void BuildMinimumSpanningTree(const int32_t start_vertex_index) noexcept;
  int32_t GetSumOfWeightsOfMst() const noexcept;

 private:
  void AddToTree(const int32_t child, const int32_t weight) noexcept;

 private:
  int32_t number_of_vertices_;
  int32_t sum_of_weights_;
  Vertex vertices_[kMaxNumberOfVertices];
  using Pair = std::pair<int32_t, int32_t>;
  std::priority_queue<Pair, std::vector<Pair>, std::greater<Pair>> priority_queue_;
};

void CallPrimAlgorithm(std::istream &input_stream) {
  input_stream.tie(0);
  std::ios::sync_with_stdio(false);
  PrimAlgorithm *minimum_spanning_tree = new PrimAlgorithm();
  try {
    int32_t number_of_vertices;
    input_stream >> number_of_vertices;
    minimum_spanning_tree->SetNumberOfVertices(number_of_vertices);
    for (int32_t from = 0; from < number_of_vertices; ++from) {
      for (int32_t to = 0; to < number_of_vertices; ++to) {
        int32_t weight;
        input_stream >> weight;
        if (weight >= 0) {
          minimum_spanning_tree->AddVertex(from, to, weight);
        }
      }
    }
    constexpr int32_t kStartVertex = 0;
    minimum_spanning_tree->BuildMinimumSpanningTree(kStartVertex);
    const int32_t sum_of_weights = minimum_spanning_tree->GetSumOfWeightsOfMst();
    std::cout << sum_of_weights << std::endl;
  } catch (...) {
    std::cerr << "ERROR: CallPrimAlgorithm()" << std::endl;
    throw;
  }
  delete minimum_spanning_tree;
}

// ****************************************************
PrimAlgorithm::PrimAlgorithm() noexcept : number_of_vertices_(0), sum_of_weights_(0) {}

PrimAlgorithm::~PrimAlgorithm() noexcept {}

void PrimAlgorithm::SetNumberOfVertices(const int32_t number_of_vertices) noexcept {
  number_of_vertices_ = number_of_vertices;
}

void PrimAlgorithm::AddVertex(const int32_t from, const int32_t to, const int32_t weight) noexcept {
  Edge edge1;
  edge1.to = to;
  edge1.weight = weight;
  vertices_[from].neighbours.push_back(edge1);
}

void PrimAlgorithm::BuildMinimumSpanningTree(const int32_t start_vertex_index) noexcept {
  constexpr int32_t kZeroDistance = 0;
  priority_queue_.push(Pair(kZeroDistance, start_vertex_index));
  while (priority_queue_.size() > 0) {
    const int32_t c_distance = priority_queue_.top().first;
    const int32_t c_vertex_index = priority_queue_.top().second;
    priority_queue_.pop();
    if (!vertices_[c_vertex_index].assigned_to_tree) {
      AddToTree(c_vertex_index, c_distance);
      for (const Edge &c_edge : vertices_[c_vertex_index].neighbours) {
        const int32_t neighbour_index = c_edge.to;
        if (!vertices_[neighbour_index].assigned_to_tree) {
          priority_queue_.push(Pair(c_edge.weight, neighbour_index));
        }
      }
    }
  }
}

int32_t PrimAlgorithm::GetSumOfWeightsOfMst() const noexcept {
  return sum_of_weights_;
}

void PrimAlgorithm::AddToTree(const int32_t child, const int32_t weight) noexcept {
  vertices_[child].assigned_to_tree = true;
  sum_of_weights_ += weight;
}

// **********************************************************************

int main() {
  try {
    CallPrimAlgorithm(std::cin);
  } catch (...) {
    std::cerr << "ERROR: main()" << std::endl;
  }
  return 0;
}

C++: #include <iostream>
using namespace std;

int n;
int a[101];

void print() {
    cout << a[0];
    for (int i = 1; i < n; i++) {
        cout << " " << a[i];
    }
    cout << endl;
}

int main() {
    while (cin >> n) {
        for (int i = 0; i < n; i++) {
            cin >> a[i];
        }
        print();
        for (int j = 1; j < n; j++) {
            int key = a[j];
            int i = j - 1;
            while (0 <= i && key < a[i]) {
                a[i + 1] = a[i];
                i--;
            }
            a[i + 1] = key;
            print();
        }
    }
}