OJ Board

I've sent the following code and got WA. Anyone can help me w/ that?

#include <iostream>
#include <string.h>
using namespace std;

#define _N 205

int adjacencyMatrix[_N][_N];
int color[_N];
int n;

bool dfs(int v, int colorToPaint = 1) {
color[v] = 1;
int nextColor = colorToPaint==1?2:1;
int ...