UVA-10615 Rooks (binary image matching)

The main topic: In a nxn box, some locations have cars, to give each car color, so that the same row and the same column of any two car color, to find a need for a minimum number of color coloring scheme.

Title Analysis: The minimum number of colors required is obviously possible, assuming that the minimum number of colors is K. If the position (I,J) is a car, then even a side i->j, get a two-dimensional graph, the K-match can be constructed out of the solution.

AC Code:

# include<iostream># include<cstdio># include<vector># include<cstring># include< Algorithm>using namespace std;# define REP (i,s,n) for (int i=s;i<n;++i) # define CL (b) memset (A,b,sizeof (a)) # Define CLL (A,b,n) Fill (a,a+n,b) const int N=105;int Inr[n],inc[n],vis[n],link[n],ans[n][n],n;char p[n][n];vector<        Int>g[n];bool dfs (int x) {REP (I,0,g[x].size ()) {int y=g[x][i];        if (Vis[y]) continue;        Vis[y]=1; if (link[y]==-1| |            DFS (Link[y])) {link[y]=x;        return true; }} return false;}    void Match () {CL (link,-1);        REP (i,0,n) {CL (vis,0);    DFS (i);    }}int Main () {int T;    scanf ("%d", &t);        while (t--) {scanf ("%d", &n);        REP (I,0,n) g[i].clear ();        REP (i,0,n) scanf ("%s", P[i]);        CL (inr,0);        CL (inc,0);            Rep (I,0,n) Rep (j,0,n) if (p[i][j]== ' * ') {++inr[i];            ++INC[J];        G[i].push_back (j); } int maxn=0;       REP (i,0,n) Maxn=max (Maxn,max (Inr[i],inc[i])); REP (I,0,n) if (INR[I]&LT;MAXN) {for (int. j=0;j<n&&inr[i]<maxn;++j) {while (inr[i]<                    MAXN&AMP;&AMP;INC[J]&LT;MAXN) {++inr[i];                    ++INC[J];                G[i].push_back (j);        }}} CL (ans,0);            REP (k,1,maxn+1) {match ();                REP (i,0,n) {int r=link[i];                if (p[r][i]== ' * ') ans[r][i]=k;                    REP (J,0,g[r].size ()) if (g[r][j]==i) {g[r].erase (G[r].begin () +j);                Break        }}} printf ("%d\n", MAXN); Rep (I,0,n) Rep (j,0,n) printf ("%d%c", Ans[i][j], (j==n-1)? '    \ n ': '); } return 0;}

　　

UVA-10615 Rooks (binary image matching)