Go: // n×nの成長度表に現れる数字を重複を許してm-1個選んで掛け合わせる時の最大値を求める
// ->掛け算型のDP

package main

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

var scanner = bufio.NewScanner(os.Stdin)

func main() {
	for scanner.Scan() {
		buf := strings.Split(scanner.Text(), " ")
		n, _ := strconv.Atoi(buf[0])
		m, _ := strconv.Atoi(buf[1])
		if n == 0 && m == 0 {
			break
		}
		growth_table := make([][]float64, n)
		for i := range growth_table {
			scanner.Scan()
			buf_ := strings.Split(scanner.Text(), " ")
			tmp := make([]float64, n)
			for j := range tmp {
				tmp[j], _ = strconv.ParseFloat(buf_[j], 64)
			}
			growth_table[i] = tmp
		}
		dp := make([][]float64, m)
		for i := range dp {
			dp[i] = make([]float64, n)
		}
		for i := range dp {
			dp[0][i] = 1
		}
		for k := 1; k < m; k++ {
			// k個使うとき...
			for i := 0; i < n; i++ {
				for j := 0; j < n; j++ {
					// 新たにgrowth_table[i][jを使うかどうか
					dp[k][j] = max(dp[k][j], dp[k-1][i]*growth_table[i][j])
					// check(dp)
				}
			}
		}
		ans := 0.0
		for i := 0; i < n; i++ {
			if dp[m-1][i] > ans {
				ans = dp[m-1][i]
			}
		}
		fmt.Printf("%.2f\n", ans)
	}
}

func max(a, b float64) float64 {
	if a < b {
		return b
	}
	return a
}

// func check(dp [][]float64) {
// 	log.Println()
// 	for i := range dp {
// 		log.Println(dp[i])
// 	}
// 	log.Println()
// }

C++: #include <iostream>
#include <fstream>
#include <vector>
#include <string>
#include <map>
#include <sstream>
#include <queue>
#include <cstdlib>
#include <algorithm>
#include <iterator>
#include <stack>
#include <list>
using namespace std;
#define INF 100000000
typedef long long int lli;
typedef pair<int,int> P;

double g[101][101];
double dp[101][101];

int main(){
	int n,m;
	while(cin>>n>>m){
		if(n==0&&m==0)  break;
		for(int i=0; i<=m; ++i){
			for(int j=0; j<n; ++j){
				dp[i][j]=0;
			}
		}
		for(int i=0; i<n; ++i){
			for(int j=0; j<n; ++j){
				cin >> g[i][j];
			}
		}
		for(int i=0; i<n; ++i){
			dp[1][i]=1.00;
		}
		for(int i=2; i<=m; ++i){
			for(int j=0; j<n; ++j){
				double tmp=dp[i][j];
				for(int k=0; k<n; ++k){
					tmp=max(tmp,dp[i-1][k]*g[k][j]);
				}
				dp[i][j]=tmp;
			}
		}
		double ans=0;
		for(int i=0; i<n; ++i){
			ans=max(ans,dp[m][i]);
		}
		ans*=100;
		ans+=0.5;
		ans=int(ans);
		a/=100;
		printf("%.2f\n",ans);
	}
	return 0;
}

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

typedef vector <double> VD;
typedef vector <VD> VVD;

VVD C;
int n; // ì¿ÌíÞ
int m; // ì¿ð^¦éñ
double answer;
double tmp;

/* æÃ~ÉT[` */
void greedy_search( int prev, int depth )
{
	if ( depth >= m ) return;

	int max_no = -1;
	double max_value = -1.0;
	for ( int i = 0; i < n; i++ )
	{
		if ( max_value < C[prev][i] )
		{
			max_no = i;
			max_value = C[prev][i];
		}
	}

	tmp *= C[prev][max_no];
	greedy_search( max_no, depth + 1 );
}

int main( void )
{
	while ( cin >> n >> m && n > 0 && m > 0 )
	{
		C = VVD( n, VD( n, 0.0 ) );

		// üÍ
		for ( int i = 0; i < n; i++ )
		{
			for ( int j = 0; j < n; j++ )
			{
				cin >> C[i][j];
			}
		}

		// Tõ
		answer = -1.0;
		for ( int i = 0; i < n; i++ )
		{
			tmp = 1.0;
			greedy_search( i, 1 );
			answer = max( answer, tmp );
		}
		cout.setf( ios::fixed );
		cout.precision( 2 );
		cout << answer << endl;
	}

	return 0;
}

C++: # include <iostream>
# include <algorithm>
# include <iomanip>

# define MAX_N 100
# define MAX_M 100

int n, m;
double dp[MAX_N][MAX_M];

double board[MAX_M][MAX_M];

int main() {
	while (1) {
		std::cin >> n >> m;
		if (n == 0 && m == 0)
			break;
		for (int i = 0; i < n; ++i)
			for (int j = 0; j < m; ++j)
				dp[i][j] = 0;
		for (int i = 0; i < m; ++i) {
			for (int j = 0; j < m; ++j)
				std::cin >> board[i][j];
		}
		std::fill(dp[0], dp[0] + m, 1);
		for (int i = 0; i < n; ++i) {
			for (int j = 0; j < m; ++j) {
				for (int k = 0; k < m; ++k) {
					dp[i][j] = std::max(dp[i][j], dp[i - 1][k] * board[k][j]);
				}
			}
		}
		double res = 0;
		for (int i = 0; i < m; ++i)
			res = std::max(res, dp[n - 1][i]);
		std::cout << std::fixed << std::setprecision(2) << res << std::endl;
	}
	return 0;
}

C++: #include <bits/stdc++.h>
#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define RFOR(i,a,b) for(int i=(b) - 1;i>=(a);i--)
#define REP(i,n) for(int i=0;i<(n);i++)
#define RREP(i,n) for(int i=n-1;i>=0;i--)

#define PB push_back
#define INF INT_MAX/3
#define ALL(a) (a).begin(),(a).end()
#define CLR(a) memset(a,0,sizeof(a))

typedef long long int ll;

using namespace std;

int main(){
    while(true){
	int m,n;
	cin >> n >> m;
	vector< vector<double> > d(n,vector<double>(n,0.0) );
	if(n == 0 && m == 0) break;
	REP(i,n)REP(j,n) cin >> d[i][j];
	double ans = 0.0;
	vector<double> a(n);
	double dp[2][101];
	memset(dp,1,sizeof(dp));
	REP(i,101) dp[0][i] = 1;
	REP(i,m-1){
	    REP(j,101) dp[1][i] = 0;
	    REP(j,n){
		REP(k,n){
		    dp[1][j] = max(dp[1][j],dp[0][j] * d[k][j]);
		}
	    }
	    swap(dp[0],dp[1]);
	}
	REP(i,n) ans = max(dp[0][i],ans);
	int t = ans * 1000;
	t = t % 10;
	if(t >= 5) ans += 0.01;
	printf("%.2f\n",ans);
    }
    return 0;
}

C++: #include <cstdio>
#include <algorithm>
using namespace std;
double tb[100][100], dp[2][100][100];
int main() {
	int n,m;
	while(scanf("%d %d",&n,&m),n) {
		for(int i=0;i<n;i++) for(int j=0;j<n;j++) {
			scanf("%lf",&tb[i][j]);
		}
		fill((double*)dp[1],(double*)dp[2],1);
		for(int i=2;i<=m;i++) for(int j=0;j<n;j++) for(int k=0;k<n;k++) {
			double mv=0;
			for(int l=0;l<n;l++) mv=max(mv,dp[(i-1)%2][k][l]);
			dp[i%2][j][k]=mv*tb[j][k];
		}
		double mv=0;
		for(int i=0;i<n;i++) for(int j=0;j<n;j++) {
			mv=max(mv,dp[m%2][i][j]);
		}
		printf("%.2lf\n",mv);
	}
}

C++: #include <iostream>
#include <algorithm>
#include <cstdio>
#include <cmath>

using namespace std;

int n,m;
double dp[100][100];
double t[100][100];

double solve(int times, int prev){
  if(dp[times][prev] != -1) return dp[times][prev];
  if(times == m) return 1;

  double tmp=-1;
  for(int i=0;i<n;i++){
    if(times == 0){
      tmp = max(tmp, solve(times+1, i) * 1);
    }else{
      tmp = max(tmp, solve(times+1, i) * t[prev][i]);
    }
  }
  
  return dp[times][prev] = tmp;
}

int main(void){
  while(cin >> n >> m){
    if(!(n|m)) break;
    fill((double *)dp, (double *)dp+101*101, -1);
    double retd;
    for(int i=0;i<n;i++){
      for(int j=0;j<n;j++){
	cin >> t[i][j];
      }
    }
    retd = solve(0,0) * 100;
    printf("%.2lf\n", round(retd) /  100);
  }
}

C++: #include<iostream>
#include<cmath>
#include<vector>

using namespace std;

const double eps = 1.0e-10;
double eq(double a, double b){ //a==b
  return abs(b-a)<eps;
}
double gt(double a, double b){ //a>b
  return !eq(a,b) && a > b;
}

int main(){
  while(true){
    int n,m;
    double answer = -1;
    cin >> n >> m;
    if( n == 0 && m == 0 ) break;
    double table[n][n];
    for(int i = 0; i < n; ++i){
      for(int j = 0; j < n; ++j){
	cin >> table[i][j];
      }
    }
    double dp[n][m];
    for(int i = 0; i < n; ++i){
      dp[i][0] = 1.0;
    }
    for(int i = 1; i < m; ++i){
      double maximum = -1;
      for(int j = 0; j < n; ++j){
	for(int k = 0; k < n; ++k){
	  double t = table[k][j] * dp[k][i-1];
	  if( gt(t,maximum) ){
	    t=maximum;
	  }
	}
      }
      dp[j][i] = t;
    }
    
    for(int i = 0; i < n; ++i){
      if( gt( dp[i][m-1], answer ) )
	answer = greedy[i];
    }
    printf("%.2lf\n",answer);

  }
  return 0;
}