HDU-2819 Swap

这题也是异列异行问题，而且任意输出一个解即可。。。

#include <cstdlib>
#include <cstdio>
#include <cmath>
#include <cstring>
#include <algorithm>
#include <fstream>
#include <iostream>

#define rep(i, l, r) for(int i=l; i<=r; i++)
#define down(i, l, r) for(int i=l; i>=r; i--)
#define N 123

using namespace std;
int read()
{
	int x=0, f=1; char ch=getchar();
	while (ch<'0' || ch>'9') { if (ch=='-') f=-1; ch=getchar(); }
	while (ch>='0' && ch<='9') { x=x*10+ch-'0'; ch=getchar(); }
	return x*f;
}

int n, m, d[N][N], k[N], x[N], y[N];
bool b[N];

bool Find(int x)
{
	rep(i, 1, n) if (d[x][i] && !b[i]) 
	{
		b[i]=1; if (!k[i] || Find(k[i])) { k[i]=x; return true; }
	}
	return false;
}

int main()
{
	while (~scanf("%d", &n))
	{
		rep(i, 1, n) rep(j, 1, n) d[i][j]=read(); 
		rep(i, 1, n) k[i]=0;
		bool can=true;
		rep(i, 1, n) 
		{
			rep(j, 1, n) b[j]=0;
			if (!Find(i)) { can=false; break; }
		}
		if (!can) { printf("-1
"); continue; } else m=0;
		rep(i, 1, n) while (k[i]!=i)
		{
			m++; x[m]=i, y[m]=k[i]; int a;
			a=k[x[m]], k[x[m]]=k[y[m]], k[y[m]]=a;
		}
		printf("%d
", m);
		rep(i, 1, m) printf("C %d %d
", x[i], y[i]);
	}
	return 0;
}