SPOJ.com - Problem BUGLIFE

[abhi2703]

SPOJ.com - Problem BUGLIFE

Here is my code can anybody detect any error in my code …please tell me…it tells no suspicious bug found in every time

#include <bits/stdc++.h>
using namespace std;
vector ar[1000001];
int vis[1000001];
int col[1000001];
bool dfs(int pos, int c)
{
vis[pos] = 1;
col[pos] = c;
for (int child : ar[pos])
{
if (vis[child] == 0) {
bool xy = dfs(child, c ^ 1);
if (xy == false)
return false;
}
else if (col[child] == col[pos]) {
return false;
}
}

}
signed main()
{
ios::sync_with_stdio(0);
cout.tie(0);
int t, n, e, a, b, dd = 1;
cin >> t;
while (t–) {
cin >> n >> e;
int xx = e;
for (int i = 1; i <= n; i++)
ar[i].clear(), vis[i] = 0, col[i] = 0;
while (xx–)
{
cin >> a >> b;
cin.tie(0);
ar[a].push_back(b);
ar[b].push_back(a);
} bool flag = true;
for (int i = 1; i <= n; i++)
{
if ( vis[i] = 0)
{
bool ff = dfs(i, 0);
if (ff == false)
flag = false;
}
}
cout << “Scenario #” << dd << “:” << “\n”; dd++;
//cout << e << n;
if (flag == true )
cout << “No suspicious bugs found!” << “\n”;
else
cout << “Suspicious bugs found!” << “\n”;
}
}

[simes]

When posting code, please put three back ticks ``` on a line by themselves both before and after the code. This stops the smart editor from interpreting it, as well as preserving the indentation.

Take another look at this line

if ( vis[i] = 0)

BUGLIFE

[abhi2703]

‘’’#include <bits/stdc++.h>
using namespace std;
vector ar[10000];
int vis[10000];
int col[10000];
bool dfs(int pos, int c)
{
vis[pos] = 1;
col[pos] = c;
for (int child : ar[pos])
{
if (vis[child] == 0) {
bool xy = dfs(child, c ^ 1);
if (xy == true)
return true;
}
else if (col[child] == col[pos]) {
return true;
}
}
}
signed main()
{
ios::sync_with_stdio(0);
cout.tie(0);
int t, n, e, a, b, dd = 1;
cin >> t;
while (t–) {
cin >> n >> e;
int xx = e;
for (int i = 1; i <= n; i++)
ar[i].clear(), vis[i] = 0, col[i] = 0;
while (xx–)
{
cin >> a >> b;
cin.tie(0);
ar[a].push_back(b);
ar[b].push_back(a);
} bool flag = false;
for (int i = 1; i <= n; i++)
{
if ( vis[i] == 0)
{
bool ff = dfs(i, 0);
if (ff == true)
flag = true;
}
}
cout << “Scenario #” << dd << “:” << “\n”; dd++;
//cout << e << n;
if (flag == false )
cout << “No suspicious bugs found!” << “\n”;
else
cout << “Suspicious bugs found!” << “\n”;
}
}’’'
now it gives runtime error sigsegv(Segmentation fault)

[simes]

…please put three back ticks ``` on a line by themselves both before and after the code…

[simes]

Check the DFS function. There’s a route through it with no return.

[abhi2703]

Thanks very much. I forgot to return false in dfs function at last. Now it runs successfully.