zoj 2770 Burn the Linked Camp

今天刚刚学差分约束系统。利用最短路求解不等式。世界真的好奇妙！感觉不等式漏下几个会导致WA！！

#include<cstdio>

#include<cstring>

#include<cmath>

#include<queue>

#include<vector>

#include<algorithm>

using namespace std;



const int maxn = 1111;

vector<int>ljb[maxn];//邻接表

int jz[maxn][maxn];//邻接矩阵

int n, m, shibai;

int c[maxn], d[maxn];

int dist[maxn];

int flag[maxn], tott[maxn];



void spfa()

{

    int ii;

    queue<int>Q;

    memset(flag, 0, sizeof(flag));

    memset(tott, 0, sizeof(tott));

    flag[n] = 1; tott[n]++;

    for (ii = 0; ii <= n; ii++) dist[ii] = 999999999;

    dist[n] = 0; Q.push(n);

    while (!Q.empty())

    {

        int hh = Q.front(); Q.pop(); flag[hh] = 0;

        for (ii = 0; ii < ljb[hh].size(); ii++)

        {

            if (jz[hh][ljb[hh][ii]] != 999999999)

            {

                if (dist[hh] + jz[hh][ljb[hh][ii]] < dist[ljb[hh][ii]])

                {

                    dist[ljb[hh][ii]] = dist[hh] + jz[hh][ljb[hh][ii]];

                    if (flag[ljb[hh][ii]] == 0)

                    {

                        Q.push(ljb[hh][ii]);

                        flag[ljb[hh][ii]] = 1;

                        tott[ljb[hh][ii]]++;

                        if (tott[ljb[hh][ii]] >= n)    { shibai = 1; break; }

                    }

                }

            }

        }

        if (shibai) break;

    }

}



int main()

{

    int i, j, u, v, k;

    while (~scanf("%d%d", &n, &m))

    {

        shibai = 0; c[0] = 0; d[0] = 0;

        for (i = 0; i <= n; i++) ljb[i].clear();

        for (i = 0; i <= n; i++)

        {

            for (j = 0; j <= n; j++)

            {

                if (i == j) jz[i][j] = 0;

                else jz[i][j] = 999999999;

            }

        }

        for (i = 1; i <= n; i++) scanf("%d", &c[i]);

        for (i = 1; i <= n; i++) d[i] = c[i] + d[i - 1];

        for (i = 0; i < m; i++)

        {

            scanf("%d%d%d", &v, &u, &k);

            jz[u][v - 1] = -k;

            ljb[u].push_back(v - 1);

            jz[v - 1][u] = d[u] - d[v - 1];

            ljb[v - 1].push_back(u);

        }

        for (i = 1; i <= n; i++)

        {

            jz[i - 1][i] = c[i];

            ljb[i - 1].push_back(i);

            jz[i][i - 1] = 0;

            ljb[i].push_back(i - 1);

        }

        spfa();

        if (shibai == 1) printf("Bad Estimations\n");

        else printf("%d\n", -dist[0]);

    }

    return 0;

}