59 lines
1.2 KiB
C++
59 lines
1.2 KiB
C++
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#include <iostream>
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#include <algorithm>
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using std::cin,std::cout,std::sort,std::max;
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constexpr int MAX_N {(int)2e5+5};
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struct City{
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int a,b;
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bool operator<(const City &that)const noexcept{
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return this->a<that.a;
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}
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} city[MAX_N];
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int n, len[MAX_N],ans;
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template<class T>
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class ReadNumber{
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char c;
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T w,n;
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public:
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ReadNumber& operator>>(T &num)noexcept{
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c=(char)0,w=1,n=0;
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while(!isdigit(c)){
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// if constexpr(!std::is_same_v<ull, T>){
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// if(c=='-')w=-1;
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// }
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c = getchar();
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}
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while(isdigit(c)){
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n = n*10 + (c-'0');
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c = getchar();
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}
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num = w*n;
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return *this;
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}
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};
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ReadNumber<int> readint;
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#define cin readint
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int main(){
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cin>>n;
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for(int i=0;i<n;i++){
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cin>>city[i].a>>city[i].b;
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len[i]=1;
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}
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sort(city,city+n);
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for(int i=0;i<n;i++){
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for(int j=i-1;j>=0;j--){
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if(city[j].b<city[i].b && len[i]<len[j]+1){
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len[i]=len[j]+1;
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}
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}
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}
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for(int i=0;i<n;i++){
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// cout<<"i:"<<i<<" "<<"len:"<<len[i]<<'\n';
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ans = max(ans,len[i]);
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}
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cout<<ans<<'\n';
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}
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