其中用set代替unique可以AC原因未知
解法
本质是在求联通块，用并查集，用暴力。
ACcode
#include<iostream>
#include<queue>
#include<cstring>
#include<string>
#include<sstream>
#include<map>
#include<vector>
#include<cstdio>
#include<cmath>
#include<algorithm>
#include<cstdlib>
#include<set>
#include<stack>
#include<ctime>
using namespace std;
#define rep(i,aa,bb) for(register int i=aa;i<=bb;i++)
#define rrep(i,aa,bb) for(register int i=aa;i>=bb;i--)
#define mset(var,val) memset(var,val,sizeof(var))
#define LL long long
#define eps 0.000001
#define inf 0x7f7f7f7f
#define llinf 1e18
#define exp 0.000001
#define pai 3.141592654
#define random(x) rand()%(x)
#define lowbit(x) x&(-x)
inline int read()
{
int x=0,y=1;char a=getchar();while ( a>'9' || a<'0'){if ( a=='-')y=-1;a=getchar();}
while ( a>='0' && a<='9' ){ x=(x<<3)+(x<<1)+a-'0'; a=getchar();}return x*y;
}
#define N 1003
int ma[N][N];int fa[N],num[N][N],tot = 0 ;
int findfa(int x){
return x == fa[x] ? x : fa[x] = findfa(fa[x]) ;
}
void unin(int x,int y){
int xfa = findfa(x); int yfa = findfa(y);
if ( xfa != yfa ){
fa[xfa] = yfa;
}
}
int main()
{
// freopen("1.txt","r",stdin);
int n = read(), m = read();
mset(num,0);
rep(i,1,n){
rep(j,1,m){
scanf(" ",&ma[i][j]);
if( ma[i][j] == 1 )
num[ i ][ j ] = ++tot;
}
}
rep(i,1,tot) fa[i] = i;
rep(i,1,n){
bool is = 0 ; int st;
rep(j,1,m){
if ( num[i][j] != 0 ){
if ( is == 0 ){
is = 1;
st = num[i][j];
}
else {
unin(st,num[i][j]);
}
}
}
is = 0 ;
}
rep(j,1,m){
bool is = 0 ; int st;
rep(i,1,n){
if ( num[i][j] != 0 ){
if ( is == 0 ){
is = 1;
st = num[i][j];
}
else {
unin(st,num[i][j]);
}
}
}
is = 0;
}
set<int>s;
rep(i,1,tot){
findfa(i);
s.insert(fa[i]);
}
cout<<s.size()<<endl;
return 0;
}
另外一种解法
#include<iostream>
#include<queue>
#include<cstring>
#include<string>
#include<sstream>
#include<map>
#include<vector>
#include<cstdio>
#include<cmath>
#include<algorithm>
#include<cstdlib>
#include<set>
#include<stack>
#include<ctime>
using namespace std;
#define rep(i,aa,bb) for(register int i=aa;i<=bb;i++)
#define rrep(i,aa,bb) for(register int i=aa;i>=bb;i--)
#define mset(var,val) memset(var,val,sizeof(var))
#define LL long long
#define eps 0.000001
#define inf 0x7f7f7f7f
#define llinf 1e18
#define exp 0.000001
#define pai 3.141592654
#define random(x) rand()%(x)
#define lowbit(x) x&(-x)
inline int read()
{
int x=0,y=1;char a=getchar();while ( a>'9' || a<'0'){if ( a=='-')y=-1;a=getchar();}
while ( a>='0' && a<='9' ){ x=(x<<3)+(x<<1)+a-'0'; a=getchar();}return x*y;
}
#define N 1003
int n,m; int ma[N][N];int row[N],col[N];
void boom(int x,int y){
ma[x][y] = 0;
if ( row[x] == 0 ){
row[x] = 1;
for (int i = 1; i <= m; i++){
if ( ma[x][i] == 1 ){
boom(x,i);
}
}
}
if ( col[y] == 0 ){
col[y] = 1;
for (int i = 1; i <= n; i++){
if ( ma[i][y] == 1 ){
boom(i,y);
}
}
}
}
int main()
{
// freopen("1.txt","r",stdin);
n = read(), m = read();
rep(i,1,n){
rep(j,1,m){
scanf(" ",&ma[i][j]);
}
}
mset(row,0) ;
mset(col,0);
int sum = 0 ;
rep(i,1,n){
rep(j,1,m){
if( ma[i][j] == 1 ){
boom(i,j);
sum++;
}
}
}
cout<<sum<<endl;
return 0;
}
