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\n"); 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\n", m);
rep(i, 1, m) printf("C %d %d\n", x[i], y[i]);
}
return 0;
}

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