排列數搜尋問題很簡單，沒做優化。

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int work[4][2]={{0,0},{2,1},{3,1},{2,3}};//可以分段賦值也可以,逐個賦值用,隔開
int n = 3;
int best = 1<<20;
int x[4] = {0,1,2,3};//排列樹的初始化
int f[4] = {0};
int bestf[4]={0};
//err:陣列賦值錯了,work後面的角標沒搞清楚,
void
 
 backTrack (int t){
    if (t > n){
        int sum = 0;
        for (int i = 1; i <= n; ++i) {
            f[i] = f[i-1] + abs(work[x[i]][0] - work[x[i-1]][1]) + work[x[i]][1];
            sum += f[i];
        }
        if (sum < best ){
            best = sum;
            for (int i = 1; i <= n; ++i) {
                bestf[i] = x[i];
            }
        }
    }
    else
 
{
        for (int i = t; i <= n; ++i) {
            swap(x[t],x[i]);
            //if ()
            backTrack(t+1);
            swap(x[t],x[i]);
        }
    }
}
int main() {
    backTrack(1);
    for (int i = 1; i <= n; ++i) {
        cout << bestf[i] << " ";
    }
    cout << endl;
    cout
 
 << best <<endl;
    return 0;
}