[BZOJ2208][JSOI2010]连通数(传递闭包+bitset)

 1 #include<cstdio> 2 #include<bitset> 3 #include<algorithm> 4 #define rep(i,l,r) for (int i=l; i<=r; i++) 5 using namespace std; 6 ?7 const int N=2010; 8 int n,ans; 9 char x;10 bitset<N>f[N];11 12 int main(){13 ????scanf("%d",&n);14 ????rep(i,1,n) rep(j,1,n) scanf(" %c",&x),f[i][j]=(x==‘1‘)|(i==j);15 ????rep(i,1,n) rep(j,1,n) if (f[j][i]) f[j]|=f[i];16 ????rep(i,1,n) ans+=f[i].count();17 ????printf("%d\n",ans);18 ????return 0;19 }