delete pics to save space

2.1609.cpp

@@ -0,0 +1,112 @@
+#include<cstdio>
+#include<cstring>
+#include<vector>
+using namespace std;
+const int maxn=1026;
+char s[maxn][maxn];
+int st[maxn];
+int n;
+void solve()
+{
+	memset(st,0,sizeof(st));
+	int i,j;
+	vector<int> black,gray;
+	int size=n,match;
+	while(size>1)
+	{
+		black.clear();gray.clear();
+		for(i=0;i<n;i++) st[i]=(st[i]==-1?-1:0);
+		for(i=1;i<n;i++)
+			if(!st[i]&&s[0][i]=='0')
+			{
+				black.push_back(i);
+				continue;
+			}
+		for(i=1;i<n;i++)
+			if(!st[i]&&s[0][i]=='1')
+				for(j=1;j<n;j++)
+					if(!st[j]&&j!=i&&s[0][j]=='0'&&s[i][j]=='1')
+					{
+						gray.push_back(i);
+						break;
+					}
+		
+		for(i=0;i<black.size();i++)
+			for(j=0;j<gray.size();j++)
+				if(!st[gray[j]]&&s[gray[j]][black[i]]=='1')
+				{
+					st[black[i]]=-1;
+					st[gray[j]]=1;
+					printf("%d %d\n",black[i]+1,gray[j]+1);
+					break;
+				}
+		
+		for(i=1;i<n;i++)
+			if(s[0][i]=='1'&&!st[i])
+			{
+				printf("1 %d\n",i+1);
+				st[i]=-1;
+				st[0]=1;
+				break;
+			}
+		
+		match=-1;
+		for(i=0;i<black.size();i++)
+			if(!st[black[i]])
+			{
+				if(match==-1) match=black[i];
+				else
+				{
+					printf("%d %d\n",match+1,black[i]+1);
+					if(s[match][black[i]]=='1')
+					{
+						st[match]=1;
+						st[black[i]]=-1;
+					}
+					else
+					{
+						st[match]=-1;
+						st[black[i]]=1;
+					}
+					match=-1;
+				}
+			}
+		
+		match=-1;
+		for(i=0;i<n;i++)
+			if(!st[i])
+			{
+				if(match==-1) match=i;
+				else
+				{
+					printf("%d %d\n",match+1,i+1);
+					if(s[match][i]=='1')
+					{
+						st[match]=1;
+						st[i]=-1;
+					}
+					else
+					{
+						st[match]=-1;
+						st[i]=1;
+					}
+					match=-1;
+				}
+			}
+		size=size/2;
+	}
+}
+int main()
+{
+#ifdef local
+	freopen("pro.in","r",stdin);
+#endif
+	while(scanf("%d",&n)==1)
+	{
+		fgets(s[0],maxn,stdin);
+		for(int i=0;i<n;i++)
+			fgets(s[i],maxn,stdin);
+		solve();
+	}
+	return 0;
+}