s[i]-s[i-8]>=need[i];        转化成：      s[i-8]<=s[i]-need[i] 0<=i<=23;
person[i]>=s[i]-s[i-1]>=0      转化成：    s[i-1]<=s[i]+0;s[i]<=s[i-1]+person[i]  

for(i=0;i<=23;i++)
        {
            edge[counter].start=i;
            edge[counter].end=(i-8+24)%24;
            edge[counter++].dis=-need[i];
            edge[counter].start=i;
            edge[counter].end=(i-1+24)%24;
            edge[counter++].dis=0;
            edge[counter].start=(i-1+24)%24;
            edge[counter].end=i;
            edge[counter++].dis=person[i];
        }