Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

const (
	MAX_N      = 200
	MAX_WEIGHT = 2000
)

type Edge struct {
	start  int
	end    int
	weight int
}

type ShortestInfo struct {
	edges    []Edge
	shortest int
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	n, err := nextInt(sc)
	if err != nil {
		panic(err)
	}

	shortestList := make([]ShortestInfo, n)
	for i := 1; i < n; i++ {
		shortestList[i] = ShortestInfo{edges: []Edge{}, shortest: MAX_N*MAX_WEIGHT + 1}
	}

	adjacentMatrix := make([][]int, n)
	for i := 0; i < n; i++ {
		adjacentMatrix[i] = make([]int, n)
		for j := 0; j < n; j++ {
			v, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			adjacentMatrix[i][j] = v
		}
	}

	mst([]int{1}, shortestList, adjacentMatrix)
	fmt.Println(shortestList)
	fmt.Println(calculateMinWeight(shortestList))
}

func calculateMinWeight(shortestList []ShortestInfo) int {
	visitedList := make([]bool, len(shortestList))
	visitedList[0] = true
	sumWeight := 0
	for !visitedAll(visitedList) {
		shortestInfo := shortestList[0]
		shortestList = shortestList[1:]
		edges := shortestInfo.edges
		for _, edge := range edges {
			if !visitedList[edge.end-1] {
				visitedList[edge.end-1] = true
				sumWeight += edge.weight
			}
		}
	}
	return sumWeight
}

func visitedAll(visitedList []bool) bool {
	for _, v := range visitedList {
		if !v {
			return false
		}
	}
	return true
}

func mst(nodeStack []int, shortestList []ShortestInfo, adjacentMatrix [][]int) {
	for len(nodeStack) > 0 {
		currentNode := nodeStack[0]
		nodeStack = nodeStack[1:]
		currentShortest := getShortest(currentNode, shortestList)
		adjacents := findAdjacents(currentNode, adjacentMatrix)
		for i := 0; i < len(adjacents); i++ {
			adj := adjacents[i]
			s := getShortest(adj.end, shortestList)
			if currentShortest.shortest+adj.weight < s.shortest || (currentShortest.shortest+adj.weight == s.shortest && len(currentShortest.edges)+1 > len(s.edges)) {
				setShortest(adj.end, adj, currentShortest, shortestList)
				nodeStack = append(nodeStack, adj.end)
			}
		}
	}
}

func getShortest(node int, shortestList []ShortestInfo) ShortestInfo {
	return shortestList[node-1]
}

func setShortest(node int, edge Edge, currentShortest ShortestInfo, shortestList []ShortestInfo) {
	newEdges := make([]Edge, len(currentShortest.edges)+1)
	for i := 0; i < len(newEdges)-1; i++ {
		newEdges[i] = currentShortest.edges[i]
	}
	newEdges[len(newEdges)-1] = edge
	shortestInfo := ShortestInfo{edges: newEdges, shortest: currentShortest.shortest + edge.weight}
	shortestList[node-1] = shortestInfo
}

func findAdjacents(currentNode int, adjacentMatrix [][]int) []Edge {
	adjacents := adjacentMatrix[currentNode-1]
	edges := []Edge{}
	for i, v := range adjacents {
		if v > 0 {
			edges = append(edges, Edge{start: currentNode, end: i + 1, weight: v})
		}
	}
	return edges
}

func nextInt(sc *bufio.Scanner) (int, error) {
	sc.Scan()
	return strconv.Atoi(sc.Text())
}

C++: #include <iostream>
#include <iomanip> // << fixed << setprecision(xxx)
#include <algorithm> // do { } while ( next_permutation(A, A+xxx) ) ;
#include <vector>
#include <string> // to_string(nnn) // substr(m, n) // stoi(nnn)
#include <complex>
#include <tuple> // get<n>(xxx)
#include <queue>
#include <stack>
#include <map> // if (M.find(key) != M.end()) { }
#include <set> // S.insert(M);
// if (S.find(key) != S.end()) { }
// for (auto it=S.begin(); it != S.end(); it++) { }
// auto it = S.lower_bound(M);
#include <random> // random_device rd; mt19937 mt(rd());
#include <cctype>
#include <cassert>
#include <cmath>
#include <cstdio>
#include <cstdlib> // atoi(xxx)
using namespace std;

#define DEBUG 0 // change 0 -> 1 if we need debug.
// insert #if<tab> by my emacs. #if DEBUG == 1 ... #end

typedef long long ll;

// const int dx[4] = {1, 0, -1, 0};
// const int dy[4] = {0, 1, 0, -1};

// const int C = 1e6+10;
// const ll M = 1000000007;

class UnionFind {
public:
  int N;
  int* root;
  int* rank;

  UnionFind(int n) : N(n) {
    root = new int[N];
    rank = new int[N];
    for (auto i = 0; i < N; ++i) {
      root[i] = i;
      rank[i] = 0;
    }
  }

  ~UnionFind() {
    delete[] root;
    delete[] rank;
  }

  int find(int x) {
    if (root[x] == x) return x;
    return root[x] = find(root[x]);
  }

  void unite(int x, int y) {
    x = find(x);
    y = find(y);
    if (x == y) return;
    if (rank[x] < rank[y]) {
      root[x] = y;
    } else {
      root[y] = x;
      if (rank[x] == rank[y]) ++(rank[x]);
    }
  }

  bool same(int x, int y) {
    return (find(x) == find(y));
  }
};

class Edge {
public:
  int src, dst, cost;
  Edge(int s, int d, int c)
    : src(s), dst(d), cost(c) {}
  friend bool operator<(const Edge& x, const Edge& y) {
    return x.cost < y.cost;
  }
};

typedef Edge State;

class Graph {
public:
  int N;
  vector<Edge>* V;
  vector<Edge> W;
  // dfs, bfs
  int* visited;
  int* from;
  int time;
  int* time_d;
  int* time_f; // dfs
  int* dist;
  int* root;
  // kruskal
  int kruskal_cost;
  vector<Edge>* kruskal_V;
  vector<Edge> kruskal_W;

  Graph(int n)
    : N(n), time(0), kruskal_cost(-1) {
    V = new vector<Edge>[N];
    from = new int[N];
    time_d = new int[N];
    time_f = new int[N];
    visited = new int[N];
    fill(visited, visited+N, 0);
    dist = new int[N];
    root = new int[N];
    kruskal_V = new vector<Edge>[N];
  }
  ~Graph() {
    delete[] V;
    delete[] from;
    delete[] time_d;
    delete[] time_f;
    delete[] visited;
    delete[] dist;
    delete[] root;
    delete[] kruskal_V;
  }

  void add_edge(int src, int dst, int cost = 1) {
    Edge e(src, dst, cost);
    V[src].push_back(e);
    W.push_back(e);
  }

  bool is_connected(int s, int t) {
    if (visited[s] == 0) {
      dfs(s);
    }
    if (visited[t] == 0) {
      dfs(t);
    }
    return (root[s] == root[t]);
  }

  void dfs(int start) {
    stack<State> S;
    S.push(State(-1, start, 0));
    while (!S.empty()) {
      State s = S.top();
      S.pop();
      if (visited[s.dst] == 0) {
        visited[s.dst] = 1;
        time_d[s.dst] = time++;
        from[s.dst] = s.src;
        dist[s.dst] = s.cost;
        root[s.dst] = start;
        S.push(s);
        for (auto x : V[s.dst]) {
          if (visited[x.dst] == 0) {
            S.push(State(s.dst, x.dst, s.cost + x.cost));
          }
        }
      } else if (visited[s.dst] == 1) {
        visited[s.dst] = 2;
        time_f[s.dst] = time++;
      }
    }
  }

  void bfs(vector<int> start) {
    assert(!start.empty());
    queue<State> Q;
    for (auto x : start) {
      Q.push(State(-1, x, 0));
    }
    while (!Q.empty()) {
      State s = Q.front();
      Q.pop();
      if (visited[s.dst] == 0) {
        visited[s.dst] = 1;
        time_d[s.dst] = time++;
        from[s.dst] = s.src;
        dist[s.dst] = s.cost;
        root[s.dst] = start[0];
        for (auto x : V[s.dst]) {
          if (visited[x.dst] == 0) {
            Q.push(State(s.dst, x.dst, s.cost + x.cost));
          }
        }
      }
    }
  }

  int kruskal() {
    if (kruskal_cost != -1) return kruskal_cost;
    sort(W.begin(), W.end());
    UnionFind u(N);
    int kruskal_cost = 0;
    for (auto e : W) {
      if (!u.same(e.src, e.dst)) {
        kruskal_V[e.src].push_back(e);
        kruskal_W.push_back(e);
        u.unite(e.src, e.dst);
        kruskal_cost += e.cost;
      }
    }
    return kruskal_cost;
  }
};

int main () {
  int n;
  cin >> n;
  Graph g(n);
  for (auto i = 0; i < n; ++i) {
    for (auto j = 0; j < n; ++j) {
      int a;
      cin >> a;
      if (a != -1) {
        g.add_edge(i, j, a);
      }
    }
  }
  cout << g.kruskal() << endl;
}