spfa求最短路模板（邻接矩阵）

int n, dis[300], mapp[300][300], used[300];int SPFA(int u){    for (int i = 1; i <= n; i++)    {        dis[i] = inf;    }    queue<int>q;    q.push(u);    used[u] = 1;    dis[u] = 0;    while (!q.empty())    {        int now = q.front();        used[now] = 0;        q.pop();        for (int i = 1; i <= n; i++)            if (dis[i] > dis[now] + mapp[now][i])            {                dis[i] = dis[now] + mapp[now][i];                if (!used[i])                {                    used[i] = 1;                    q.push(i);                }            }    }}void inti(){    for (int i = 1; i <= n; i++)        for (int j = 1; j <= n; j++)            if (i == j)            {                mapp[i][j] = 0;            }            else            {                mapp[i][j] = inf;            }}