POJ 1789 Truck History

解题思路：prim算法求解最小生成树

#include<iostream>
using namespace std;

#define MaxNum 1e8

inline int distance(char *a, char *b)
{
    int t = 0;
    for (int i = 0; i < 7; i++)
        if (a[i] != b[i])
            t++;
    return t;
}
int main()
{
    int n, min, start, tempS, totalDist;
    char input[2001][8];
    int dist[2001];
    bool visited[2001];

    while (cin >> n && n)
    {
        dist[0] = 0;
        start = 0;

        fill(&dist[1], &dist[n], MaxNum);
        memset(visited, 0, sizeof(bool) * 2001);

        for (int i = 0; i < n; i++)
            cin >> input[i];

        while (start != -1)
        {
            visited[start] = true;
            tempS = -1;
            min = MaxNum;

            for (int i = 0; i < n; i++)
            {
                if (!visited[i])
                {
                    if (dist[i] != 1)
                    {
                        int l = distance(input[start], input[i]);
                        if (dist[i] > l)
                            dist[i] = l;
                    }    
                    if (min > dist[i])
                    {
                        min = dist[i];
                        tempS = i;
                    }
                }
            }
            start = tempS;
        }
        totalDist = 0;
        for (int i = 0; i < n; i++)
            totalDist += dist[i];
        cout << "The highest possible quality is 1/" << totalDist << "." << endl;
    }
    return 0;
}