Submission #3560871

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Source Code Expand

var
	n,m,a,b,i,k,cnt:Longint;
	x,y:array[1..200]of Longint;
	dp:array[0..200,1..100]of int64;
begin
	read(n,a,b,m);
	for i:=1 to m do begin
		read(x[i],y[i]);
	end;
	dp[0,a]:=1;
	k:=0;
	while True do begin
		inc(k);
		for i:=1 to m do begin
			inc(dp[k,y[i]],dp[k-1,x[i]]);
			inc(dp[k,x[i]],dp[k-1,y[i]]);
		end;
		if dp[k,b]>0 then begin
			writeln(dp[k,b]mod 1000000007);
			exit;
		end;
	end;
end.

Submission Info

Compile Error

/usr/bin/ld.bfd: warning: ./link.res contains output sections; did you forget -T?

Judge Result