Go: package main

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

const (
	WHITE int = iota
	GRAY
	BLACK
)

type graph struct {
	G [][]int
	C []int
	D []int
	P []int
}

var INFTY = 1 << 32

func constructGraph() *graph {
	sc := bufio.NewScanner(os.Stdin)
	sc.Scan()
	n, _ := strconv.Atoi(sc.Text())

	g := make([][]int, n)
	c := make([]int, n)
	d := make([]int, n)
	p := make([]int, n)

	for i := 0; i < n; i++ {
		sc.Scan()
		fields := strings.Fields(sc.Text())
		g[i] = toIntSlice(fields)
	}

	return &graph{g, c, d, p}
}

func (g *graph) initMst() {
	for i := 0; i < len(g.G); i++ {
		g.C[i] = WHITE
		g.D[i] = INFTY
	}
	g.D[0] = 0
	g.P[0] = -1
}

func (g *graph) primMst() int {
	g.initMst()

	var u int
	for {
		mincost := INFTY
		for i := 0; i < len(g.G); i++ {
			if g.C[i] != BLACK && g.D[i] < mincost {
				mincost = g.D[i]
				u = i
			}
		}

		if mincost == INFTY {
			break
		}

		g.C[u] = BLACK

		for i := 0; i < len(g.G); i++ {
			if g.C[i] != BLACK && g.existEdge(u, i) {
				if g.G[u][i] < g.D[i] {
					g.D[i] = g.G[u][i]
					g.P[i] = u
				}
			}
		}
	}

	totalCost := 0
	for _, cost := range g.D {
		totalCost += cost
	}
	return totalCost
}

func (g *graph) existEdge(u, v int) bool {
	return g.G[u][v] != INFTY && g.G[v][u] != INFTY
}

func toIntSlice(s []string) []int {
	a := make([]int, len(s))
	for i, v := range s {
		num, _ := strconv.Atoi(v)
		if num == -1 {
			num = INFTY
		}
		a[i] = num
	}
	return a
}

func main() {
	g := constructGraph()
	fmt.Println(g.primMst())
}

Python: def memoize(f):  
    cache = {}  
    def helper(x):  
        if x not in cache:              
            cache[x] = f(x)  
        return cache[x]  
    return helper 

def split_apex(a):
    if len(a) == 2:
        yield (a[0],), (a[1],)
    else:
        for i in range(0, len(a)):
            yield (a[i],), a[:i] + a[i + 1:]

@memoize
def wait(a):
    global g
    if len(a) == 1:
        return 0
    return min(calc_wait(apex, apices) for apex, apices in split_apex(a))

def calc_wait(apex, apices):
    global g
    w = [g[apex[0]][i] for i in apices if g[apex[0]][i] != -1]
    return  wait(apex) + wait(apices) + (min(w) if len(w) else 200000)

n = int(input())
g = [None] + [[None] + list(map(int, input().split())) for _ in range(n)]

a = tuple(i + 1 for i in range(n))
print(wait(a))

Python: def prim(cost):
    sumcost = 0
    V = len(cost)
    mincost = [float('inf')] * V
    used = [False] * V
    mincost[0] = 0
    while True:
        j = -1
        for i in range(V):
            if not used[i] and (j == -1 or mincost[i] < mincost[j]):
                j = i
        if j == -1:
            break
        used[j] = True
        sumcost = sumcost + mincost[j]
        for i in range(V):
            if cost[i][j] == -1:
                continue
            mincost[i] = min(mincost[i], cost[j][i])
    return sumcost
 
n = int(raw_input())
A = [0] * n
for i in range(n):
    A[i] = map(int, raw_input().split())
 
result = prim(A)
print(result)

Python: n = int(input())
#簡単のため、プリム法で回答する
data = []
for _ in range(n):
    line = list(map(int,input()[1:].split(' ')))
    for i in range(len(line)):
        if line[i] == -1:
            line[i] = 2001
    data.append(line)

been = [0]
unBeen = []
count = 0
while True:
    minIndex = [0,0]
    min = 2001
    for ele in been:
        for i in range(len(data[ele])):
            if min > data[ele][i] and not i in been:
                min = data[ele][i]
                minIndex = [ele,i]

    count += data[minIndex[0]][minIndex[1]]
    data[minIndex[0]][minIndex[1]] = 2001
    data[minIndex[1]][minIndex[0]] = 2001
    been.append(minIndex[1])
    if len(been) == n:
        break

print(count)

Python: n=int(input())
M=[list(map(int,input().split()))for _ in[0]*n]
d=[0]+[1e4]*n
b=[1]*n
a=0
while 1:
 u=-1
 for i in range(n):
  if b[i]and(u<0 or d[i]<d[u]):u=i
 if u<0:break
 b[u]=0
 a+=d[u]
 for v in range(n):
  t=M[u][v]
  if t+1 and d[v]>t:d[v]=t
print(a)

Python: n = int(input())
M = [list(map(int, input().split())) for _ in range(n)]
INF = 100000000000
color = ['White']*n
d = [INF]*n
p = [-1]*n
d[0] = 0
sum = 0

while True:
    minct = INF
    u = -1
    for i in range(n):
        if color[i] != 'Black' and d[i] < minct:
            minct = d[i]
            u = i
    if minct == INF:
        break
    color[u] = 'Black'
    for j in range(n):
        if color[j] != 'Black' and M[u][j] != -1:
            if M[u][j] < d[j]:
                d[j] = M[u][j]
                p[j] = u
                color[j] = 'Gray'
for k in range(n):
    if p[k] != -1:
        sum += M[k][p[k]]
print(sum)

Python: INF = 9999


def prim(M):
    n = len(M)
    color = [0] * n
    d = [INF] * n
    d[0] = 0

    while True:
        minv = INF
        u = -1
        for i in range(n):
            # Black:2
            if minv > d[i] and color[i] != 2:
                u = i
                minv = d[i]
        if u == -1: break
        color[u] = 2

        for v in range(n):
            if color[v] != 2 and M[u][v] != INF:
                if d[v] > M[u][v]:
                    d[v] = M[u][v]
    return sum(d)


if __name__ == '__main__':
    n = int(input())
    A = []
    for i in range(n):
        src = input()
        dst = src.replace('-1', str(INF))
        ai = list(map(int, dst.split()))
        A.append(ai)
    print(prim(A))

Python: INFINITY = 10 ** 10
WHITE = 0
GRAY = 1
BLACK = 2


n = int(input())
M = [[INFINITY] * n for _ in range(n)]

for i in range(n):
    for j, weight in enumerate(map(int, input().split())):
        if weight == -1:
            weight = INFINITY

        M[i][j] = weight


def prim():
    color = [WHITE] * n
    d = [INFINITY] * n
    p = [None] * n

    d[0] = 0
    p[0] = -1

    while True:
        cost_min = INFINITY
        for i in range(n):
            if color[i] != BLACK and d[i] < cost_min:
                cost_min = d[i]
                top_now = i

        if cost_min == INFINITY:
            break
    
        color[top_now] = BLACK

        for v in range(n):
            if color[v] == BLACK or M[top_now][v] == INFINITY:
                continue

            if M[top_now][v] < d[v]:
                d[v] = M[top_now][v]
                p[v] = top_now
                color[v] = GRAY

    return sum(d)

cost_min = prim()
print(cost_min)

Python: def prim(n, M):
    color = [0 for _ in range(n)]
    d = [5000 for _ in range(n)]
    p = [-1 for _ in range(n)]

    d[0] = 0

    while True:
        mincost = 100000
        u = -1

        for i, dt in enumerate(d):
            if dt < mincost and color[i] != 1:
                mincost = dt
                u = i

        # ??´??°???????????£?????´???
        if mincost == 100000:
            break

        color[u] = 1

        for v in range(n):
            # ????????????, ?????????????¨???????????????¨??????
            if M[u][v] != 5000 and color[v] != 1:
                if M[u][v] < d[v]:
                    d[v] = M[u][v]
                    p[v] = u

    all_sum = 0

    for i, p_dt in enumerate(p):
        if p_dt != -1:
            all_sum += M[i][p_dt]

    return all_sum


def main():
    n = int(input())
    M = []

    for _ in range(n):
        dt = input().split(' ')
        M.append([5000 if int(d) == -1 else int(d) for d in dt])

    print(M)

    answer = prim(n, M)

    print(answer)

if __name__ == '__main__':
    main()

Python: v = int(input())
G= [[int(i) for i in input().split()] for i in range(v)]
        
def prim(G, v):
    Vn = set([1])
    En = set([])
    V = set(range(1, v+1))
    while Vn != V:
        m = float('inf')
        for u in Vn:
            for v in V - Vn:
                if G[u - 1][v - 1] == -1:continue
                if G[u - 1][v - 1] < m:
                    m = G[u - 1][v -1]
                    k = (u,v)
        Vn.add(k[1])
        En.add(k)
    return En

print(sum(G[u - 1][v -1] for u,v in prim(G, v)))