zoj 2770 Burn the Linked Camp 差分约束

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最近状态太散漫，一天才写了这一题，很基础的差分约束，直接写出关系式即可。注意边数开大点

/*author:jxylang:C/C++university:China,Xidian University**If you need to reprint,please indicate the source***/#include <iostream>#include <cstdio>#include <cstdlib>#include <cstring>#include <queue>#define INF 1E9using namespace std;int Dis[1005];int U[100005];int next[100005];int W[100005];int cnt;int first[1005];int n,m;int add(int v,int u,int w){    next[cnt]=first[v];    first[v]=cnt;    U[cnt]=u;    W[cnt]=w;    cnt++;}bool inq[1005];int dq[1005];bool spfa(int v){    memset(Dis,63,sizeof(Dis));    memset(inq,0,sizeof(inq));    memset(dq,0,sizeof(dq));    queue<int> q;    q.push(v);    Dis[v]=0;    int i,u,now,t;    while(!q.empty())    {        v=q.front();q.pop();        inq[v]=0;dq[v]++;        if(dq[v]>=n)return 1;        for(i=first[v];i!=-1;i=next[i])        {            u=U[i];            t=Dis[v]+W[i];            if(t>=Dis[u])continue;            Dis[u]=t;            if(inq[u])continue;            inq[u]=1;            q.push(u);        }    }    return 0;}int main(){    while(~scanf("%d%d",&n,&m))    {        cnt=0;        memset(first,-1,sizeof(first));        int i,v,u,s;        for(i=1;i<=n;i++)        {            scanf("%d",&s);            add(i-1,i,s);            add(i,i-1,0);        }        for(i=0;i<m;i++)        {            scanf("%d%d%d",&u,&v,&s);            add(v,u-1,-s);        }        if(spfa(n))printf("Bad Estimations\n");        else printf("%d\n",-Dis[0]);    }}