Go: package main

import (
	"fmt"
	"math"
)

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

	p := make([]float64, n+1)
	q := make([]float64, n+1)
	psum := make([]float64, n+2) // i番目はi-1までの和とする
	qsum := make([]float64, n+2) // i番目はi-1までの和とする
	for i := 1; i <= n; i++ {
		fmt.Scan(&p[i])
		psum[i+1] = psum[i] + p[i]
	}
	for i := 0; i <= n; i++ {
		fmt.Scan(&q[i])
		qsum[i+1] = qsum[i] + q[i]
	}

	dp := make([][]float64, n+1)
	for i := 0; i <= n; i++ {
		dp[i] = make([]float64, n+1)
	}

	// calc
	for d := 0; d <= n; d++ {
		for l := 0; l+d <= n; l++ {
			r := l+d
			if l == r {
				dp[l][r] = q[l]
				continue
			}

			dp[l][r] = 1 << 30
			// iは中心となるnode
			for i := l+1; i <= r; i++ {
				left := dp[l][i-1] + psum[i] - psum[l+1] + qsum[i] - qsum[l]
				right := dp[i][r] + psum[r+1] - psum[i+1] + qsum[r+1] - qsum[i]
				dp[l][r] = math.Min(dp[l][r], p[i] + left + right)
			}
		}
	}

	fmt.Printf("%.8f\n", dp[0][n])
}

C++: #ifdef LOCAL
#pragma GCC optimize ("O0")
#else
#pragma GCC optimize ("O3")
#endif


#include <bits/stdc++.h>


using namespace std;

using ll = long long;
const int INF = 1e9 + 7;
const int MOD = INF;
const ll INF_LL = 1e18 + 7;

#define __overload3(_1, _2, _3, name,...) name
#define rep(...) __overload3(__VA_ARGS__, repFromUntil, repUntil, repeat)(__VA_ARGS__)
#define repeat(times) repFromUntil(__name, 0, times)
#define repUntil(name, times) repFromUntil(name, 0, times)
#define repFromUntil(name, from, until) for (int name = from, name##__until = (until); name < name##__until; name++)
#define repFromTo(name, from, to) repFromUntil(name, from, to + 1)
#define repr(...) __overload3(__VA_ARGS__, reprFromUntil, reprUntil, repeat)(__VA_ARGS__)
#define reprUntil(name, times) reprFromUntil(name, 0, times)
#define reprFromUntil(name, from, until) for (int name = until - 1, name##__from = (from); name >= name##__from; name--)
#define reprFromTo(name, from, to) reprFromUntil(name, from, to + 1)

#define debugos OUT
#ifdef LOCAL
#define debug(v) {printf("L%d %s > ",__LINE__,#v);debugos<<(v)<<newl;}
#define debugv(v) {printf("L%d %s > ",__LINE__,#v);for(auto e:(v)){debugos<<e<<" ";}debugos<<newl;}
#define debuga(m,w) {printf("L%d %s > ",__LINE__,#m);for(int x=0;x<(w);x++){debugos<<(m)[x]<<" ";}debugos<<newl;}
#define debugaa(m,h,w) {printf("L%d %s >\n",__LINE__,#m);for(int y=0;y<(h);y++){for(int x=0;x<(w);x++){debugos<<(m)[y][x]<<" ";}debugos<<newl;}}
#else
#define debug(v) {}
#define debugv(v) {}
#define debuga(m,w) {}
#define debugaa(m,h,w) {}
#endif

#define newl "\n"

#define all(iter) begin(iter), end(iter)


template <class T> bool chmin(T& var, T x) {
  if (var > x) {
    var = x;
    return true;
  } else return false;
}
template <class T> bool chmax(T& var, T x) {
  if (var < x) {
    var = x;
    return true;
  } else return false;
}

class MyScanner {
  public:
    template<typename T> void input_integer(T& var) {
        var = 0; T sign = 1;
        int cc = getchar();
        for (; cc<'0' || '9'<cc; cc = getchar())
            if (cc == '-') sign = -1;
        for (; '0' <= cc && cc <= '9'; cc = getchar())
            var = (var << 3) + (var << 1) + cc - '0';
        var = var * sign;
    }
    int c() { char c; while (c = getchar(), c == ' ' or c == '\n'); return c; }
    MyScanner& operator>>(char& var) { var = c(); return *this; }
    MyScanner& operator>>(int& var) { input_integer<int>(var); return *this; }
    MyScanner& operator>>(ll& var) { input_integer<ll>(var); return *this; }
    MyScanner& operator>>(string& var) {
        int cc = getchar();
        for (; !isvisiblechar(cc); cc = getchar());
        for (; isvisiblechar(cc); cc = getchar())
            var.push_back(cc);
        return *this;
    }
    operator int() {
      int n;
      *this >> n;
      return n;
    }
    operator ll() {
      ll n;
      *this >> n;
      return n;
    }
    private:
      int isvisiblechar(int c) {
        return 0x21 <= c && c <= 0x7E;
      }
};
class MyPrinter {
  public:
    template<typename T>
    void output_integer(T var) {
        if (var == 0) { putchar('0'); return; }
        if (var < 0)
            putchar('-'),
            var = -var;
        char stack[32]; int stack_p = 0;
        while (var)
            stack[stack_p++] = '0' + (var % 10),
            var /= 10;
        while (stack_p)
            putchar(stack[--stack_p]);
    }
    MyPrinter& operator<<(char c) { putchar(c); return *this; }
    template <typename T>
    MyPrinter& operator<<(T var) { output_integer<T>(var); return *this; }
    MyPrinter& operator<<(char* str_p) { while (*str_p) putchar(*(str_p++)); return *this; }
    MyPrinter& operator<<(const char* str_p) { while (*str_p) putchar(*(str_p++)); return *this; }
    MyPrinter& operator<<(const string& str) {
        const char* p = str.c_str();
        const char* l = p + str.size();
        while (p < l) putchar(*p++);
        return *this;
    }
    // MyPrinter& operator<<(const modint& var) { output_integer<ll>(var.value); return *this; }
    template <typename T>
    void operator()(T x) {
        *this << x << newl;
    }
};
MyScanner IN;
MyPrinter OUT;


int main() {
  int n;
  scanf("%d", &n);
  vector<double> p(n), q(n+1);
  rep(i, n) scanf("%lf", p.begin()+i);
  rep(i, n+1) scanf("%lf", q.begin()+i);

  vector<double> p_s(n+1, 0), q_s(n+2, 0), w(n+2, 0);
  rep(i, n) p_s[i+1] = p_s[i] + p[i];   // p[r] - p[l] : [l, r)
  rep(i, n+1) q_s[i+1] = q_s[i] + q[i];
  auto s = [&](int l, int r){ return (p_s[r] - p_s[l]) + (q_s[r+1] - q_s[l]); };  // w(l, r) : key [l, r)

  double dp[n+1][n+1];  // dp[l][r] : [l, r)
  fill(dp[0], dp[n+1], INF);
  rep(i, n+1) dp[i][i] = q[i];

  rep(w, 1, n+1) {
    rep(i, n-w+1) {
      int j = i + w;
      rep(r, i, j) chmin(dp[i][j], dp[i][r] + dp[r+1][j] + s(i, j));
      // printf("dp[%d][%d] = %.5lf\n", i, j, dp[i][j]);
    }
  }
  printf("%.7lf", dp[0][n]);
}

C++: #include <stdio.h>
#include <iostream>
#include <algorithm>

using namespace std;
#define N 501

int main(){
    int n;
    double p[N],q[N];
    double pSum[N][N],qSum[N][N];
    double d[N][N];
    double t;
    
    cin >> n;
    
    for(int i = 0;i < n;++i){
        cin >> p[i];
    }
    
    for(int i = 0;i < n + 1;++i){
        cin >> q[i];
        d[i][i] = q[i];
    }
    
     // p
    for(int i = 0;i < n;++i){
        pSum[i][i] = p[i];
        for(int j = i + 1;j < n;++j){
            pSum[i][j] = pSum[i][j - 1] + p[j];
        }
    }
    
    // q
    for(int i = 0;i < n + 1;++i){
        qSum[i][i] = q[i];
        for(int j = i + 1;j < n + 1;++j){
            qSum[i][j] = qSum[i][j - 1] + q[j];
        }
    }
    
    for(int i = 1;i < n + 1;++i){
        for(int j = 0;j < (n + 1) - i;++j){
            d[j][j + i] = __DBL_MAX__;
            for(int k = 0;k < i;++k){
                t = d[j][j + k] + d[j + k + 1][j + i] + pSum[j][j + i - 1] + qSum[j][j + i];
                d[j][j + i] = min(d[j][j + i], t);
            }
        }
    }
    
    printf("%.8lf \n",d[0][n]);
    
    return 0;
}

C++: #define _CRT_SECURE_NO_WARNINGS

#include<iostream>
#include<functional>
#include<algorithm>
#include<stack>
#include<queue>
#include<iomanip>
#include<set>
#include<map>
#include<utility>
#include<string>
#include<vector>

using namespace std;

#define LL long long

int n;
double cost[1002],sum[1005]={},memo[1005][1005];

double exp(int l,int r){
	if(memo[l][r]!=-1.0)return memo[l][r];
	double ret=1000000000.0;
	if(l==r)ret=cost[l];
	else{
		for(int k=l+1;k<r;k+=2)
			ret=min(ret,exp(l,k-1)+exp(k+1,r)+sum[r]-(l==0?0.0:sum[l-1]));
	}
	return memo[l][r]=ret;
}


int main() {
	cin>>n;
	for(int i=0;i<=2*n+2;i++)for(int j=0;j<=2*n+2;j++)memo[i][j]=-1.0;
	for(int i=1;i<=n;i++)cin>>cost[2*i];
	for(int i=0;i<=n;i++)cin>>cost[2*i+1];
	for(int i=1;i<=2*n+2;i++)sum[i]=cost[i]+sum[i-1];
	cout<<fixed<<exp(1,2*n+1)<<endl;
	return 0;
}