g-strongly Connected-hdu 4635 (for connected components)

Test instructions: To give you a diagram, ask the maximum number of edges can be added so that the graph is still not strong connected graph, if the original image is strongly connected output '-1 ' analysis: The first to find out the connected components of the indentation, because it is the most added edge, so can be seen as two parts x, Y, only part of the other part of So is x* (x+1) +x*y+y* (y+1)-m, only need to come out of the degree or the minimum point of 0 of the connected component can be. #include <stdio.h>
#include <string.h>
#include <algorithm>
usingnamespaceStd

ConstintMAXN = 1e5+5;
Const intoo = 1e9;

structedge{intV, Next;} E[MAXN];
intHEAD[MAXN], CNT;
voidAddedge (intUintV
{
E[CNT].V = v;
E[cnt].next = Head[u];
Head[u] = cnt++;
}

intDFN[MAXN], LOW[MAXN], Index;
intSTACK[MAXN], top, INSTACK[MAXN];
intBLG[MAXN], BNT, NBLG[MAXN];///What is the connected component and how many points are there in the connected component?
intOUTEDGE[MAXN], INEDGE[MAXN];

voidInIt (intN
{
CNT = Index = top = BNT =0;
for(intI=0; i<=n; i++)
{
Head[i] =-1;
Dfn[i] =0;
Nblg[i] =0;
Outedge[i] =0;
Inedge[i] =0;
}
}
voidTarjan (intU
{
intV

Low[u] = dfn[u] = ++index;
Stack[++top] = u;
Instack[u] =true;

for(intJ=head[u]; j!=-1; J=e[j].next)
{
v = e[j].v;
if(!dfn[v])
{
Tarjan (v);
Low[u] = min (Low[u], low[v]);
}
Elseif(Instack[v] = =true)
Low[u] = min (Low[u], dfn[v]);
}

if(Low[u] = = Dfn[u])
{
++BNT;
Do
{
v = stack[top--];
INSTACK[V] =false;
BLG[V] = BNT;
nblg[bnt]++;
}
while(U! = v);
}
}

intMain ()
{
intT, t=1;

scanf"%d", &t);

while(t--)
{
intI, J, u, V, N, M;

scanf"%d%d", &n, &m);

InIt (N);

for(i=0; i<m; i++)
{
scanf"%d%d", &u, &v);
Addedge (U, v);
}

for(i=1; i<=n; i++)
{
if(!dfn[i])
Tarjan (i);
}

for(i=1; i<=n; i++)
for(J=head[i]; j!=-1; J=e[j].next)
{
v = e[j].v;
if(Blg[i]! = Blg[v])
{
inedge[Blg[v]]++;
outedge[Blg[i]]++;
}
}

intx, Y=oo;

for(i=1; i<=bnt; i++)
{
if(!outedge[i] | |!inedge[i])
y = min (y, nblg[i]);
}

x = n-y;

if(BNT = =1)
printf"Case %d: -1\n", t++);
Else
printf"Case %d:%lld\n", t++, (Long Long) x* (x1) +x*y+y* (y1)-M);
}

return0; 

}

g-strongly Connected-hdu 4635 (for connected components)