LuoguP1020 导弹拦截 （LIS）

最长不降和单升

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#define R(a,b,c) for(register int  a = (b); a <= (c); ++ a)
#define nR(a,b,c) for(register int  a = (b); a >= (c); -- a)
#define Max(a,b) ((a) > (b) ? (a) : (b))
#define Min(a,b) ((a) < (b) ? (a) : (b))
#define Fill(a,b) memset(a, b, sizeof(a))
#define Abs(a) ((a) < 0 ? -(a) : (a))
#define Swap(a,b) a^=b^=a^=b
#define ll long long

#define ON_DEBUG

#ifdef ON_DEBUG

#define D_e_Line printf("\n\n----------\n\n")
#define D_e(x)  cout << #x << " = " << x << endl
#define Pause() system("pause")
#define FileOpen() freopen("in.txt","r",stdin);

#else

#define D_e_Line ;
#define D_e(x)  ;
#define Pause() ;
#define FileOpen() ;

#endif

struct ios{
    template<typename ATP>ios& operator >> (ATP &x){
        x = 0; int f = 1; char c;
        for(c = getchar(); c < '0' || c > '9'; c = getchar()) if(c == '-')  f = -1;
        while(c >= '0' && c <= '9') x = x * 10 + (c ^ '0'), c = getchar();
        x*= f;
        return *this;
    }
}io;
using namespace std;

const int N = 1000007;

int a[N], b[N];
int main(){
    int n = 0;
    while(~scanf("%d", &a[++n]));
    --n; //!

    int len = 1;
    b[1] = a[1];
    R(i,2,n){
        if(a[i] <= b[len]) b[++len] = a[i];
        else{
            *upper_bound(b + 1, b + len + 1, a[i], greater<int>()) = a[i]; //! greater<int>()
        }
    }
    printf("%d\n", len);

    len = 1;
    b[1] = a[1];
    R(i,2,n){
        if(a[i] > b[len]) b[++len] = a[i];
        else{
            *lower_bound(b + 1, b + len + 1, a[i]) = a[i];
        }
    }
    printf("%d", len);

    return 0;
} 

原文地址：https://www.cnblogs.com/bingoyes/p/11365958.html