排序后贪心或根据第二关键字找最长下降子序列
#pragma comment(linker, "/STACK:1024000000,1024000000") #include<cstdio> #include<cstring> #include<cstdlib> #include<algorithm> #include<iostream> #include<sstream> #include<cmath> #include<climits> #include<string> #include<map> #include<queue> #include<vector> #include<stack> #include<set> using namespace std; typedef long long ll; typedef unsigned long long ull; typedef pair<int,int> pii; #define pb(a) push(a) #define INF 0x1f1f1f1f #define lson idx<<1,l,mid #define rson idx<<1|1,mid+1,r #define PI 3.1415926535898 template<class T> T min(const T& a,const T& b,const T& c) { return min(min(a,b),min(a,c)); } template<class T> T max(const T& a,const T& b,const T& c) { return max(max(a,b),max(a,c)); } void debug() { #ifdef ONLINE_JUDGE #else freopen("in.txt","r",stdin); freopen("d:\out1.txt","w",stdout); #endif } int getch() { int ch; while((ch=getchar())!=EOF) { if(ch!=' '&&ch!=' ')return ch; } return EOF; } const int maxn=5005; struct node { int l,w; bool operator < (const node &ant) const { return l<ant.l||l==ant.l&&w<ant.w; } }; node da[maxn]; int vis[maxn]; int main() { int t; scanf("%d", &t); for(int ca = 1; ca <= t; ca++) { int n; scanf("%d", &n); for(int i = 0; i < n; i++) scanf("%d%d", &da[i].l, &da[i].w); sort(da, da + n); memset(vis,0,sizeof(vis)); int res=0; for(int cnt=0;;) { res++; int curl=-1,curw=-1; for(int i=0;i<n;i++) { if(!vis[i]&&da[i].l>=curl&&da[i].w>=curw) { vis[i] = 1; cnt++; curl=da[i].l;curw=da[i].w; } } if(cnt==n)break; } printf("%d ",res); } return 0; }