POJ 1734

被计组实验真冲昏了头脑。。水一发先。

最小环+记录路径；

几个sb点。题目没看，以为是单向边。每次记录路径递归写重（开头结尾多记录一遍）。重边忘处理。

#include <cstdio>
#include <cstring>
#define INF 10000000

using namespace std;

int n, m, x, y, mini, minj, g[105][105], k;
int w[105][105], f[105][105], ans[105], min;
int now;

void find(int x, int y)
{
    if(g[x][y] == 0)
        return;
    find(x, g[x][y]);
    ans[now ++] = g[x][y];
    find(g[x][y], y);
}

int main()
{
    scanf("%d%d", &n, &m);
    min = INF;
    for(int i = 1; i <= n; i ++)
        for(int j = 1; j <= n; j ++)
        {
            w[i][j] = INF;
            f[i][j] = INF;
        }
    for(int i = 0; i < m; i ++)
    {
        scanf("%d%d", &x, &y);
        scanf("%d", &k);
        if(f[x][y] > k)
            f[x][y] = f[y][x] = w[y][x] = w[x][y] = k;
    }

    for(int k = 1; k <= n; k ++)
    {
        mini = 0, minj = 0;
        for(int i = 1; i < k; i ++)
            for(int j = 1; j < k; j ++)
                if(i != j)
                if(min > w[k][i]+f[i][j]+w[j][k])
                {
                    min = w[k][i]+f[i][j]+w[j][k];
                    mini = i, minj = j;
                }
        // printf("%d %d %d %d\n", k, min, mini, minj);
        if(mini != 0)
        {
            ans[0] = minj;
            ans[1] = k;
            ans[2] = mini;
            now = 3;
            find(mini, minj);
        }
        for(int i = 1; i <= n; i ++)
            for(int j = 1; j <= n; j ++)
                if(f[i][j] > f[i][k]+f[k][j])
                {
                    f[i][j] = f[i][k]+f[k][j];
                    g[i][j] = k;
                }
    }
    // printf("%d\n", min);
    if(min < INF)
        for(int i = 0; i < now; i ++)
            if(i != now-1)
                printf("%d ", ans[i]);
            else
                printf("%d\n", ans[i]);
    else
        printf("No solution.\n");
    return 0;
}