Given an N*N matrix with each entry equal to 0 or 1. You can swap any two rows or any two columns. Can you find a way to make all the diagonal entries equal to 1?
Input
There are several test cases in the input. The first line of each test case is an integer N (1 <= N <= 100). Then N lines follow, each contains N numbers (0 or 1), separating by space, indicating the N*N matrix.
Output
For each test case, the first line contain the number of swaps M. Then M lines follow, whose format is “R a b” or “C a b”, indicating swapping the row a and row b, or swapping the column a and column b. (1 <= a, b <= N). Any correct answer will be accepted, but M should be more than 1000.
If it is impossible to make all the diagonal entries equal to 1, output only one one containing “-1”.
Sample Input
2 0 1 1 0 2 1 0 1 0
Sample Output
1 R 1 2 -1
#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
typedef long long ll;
const int N=111;
const int inf=0x3f3f3f3f;
int x[N],y[N],a[N][N],match[N],b[N];
int n;
int dfs(int x)
{
for(int i=1; i<=n; i++)
if(!b[i]&&a[x][i])
{
b[i]=1;
if(!match[i]||dfs(match[i]))
{
match[i]=x;
return 1;
}
}
return 0;
}
int main()
{
int i,j;
/*
while(1)
{
scanf("%d",&n);
}//提交会超时
*/
while(~scanf("%d",&n))
{
for(i=1; i<=n; i++)
for(j=1; j<=n; j++)
scanf("%d",&a[i][j]);
memset(match,0,sizeof(int)*(n+4));
int s=0;
for(i=1; i<=n; i++)
{
memset(b,0,sizeof(int)*(n+4));
if(dfs(i))
s++;
}
if(s<n)
{
puts("-1");
continue;
}
int k=0;
for(i=1; i<=n; i++)
{
while(match[i]!=i)// 行列不对应,主对角线,列=行
{
x[k]=match[i];
y[k++]=i;
swap(match[i],match[match[i]]);
}
}
printf("%d\n",k);
for(i=0; i<k; i++)
printf("C %d %d\n",y[i],x[i]);
}
return 0;
}