Luogu2869 [USACO07DEC]美食的食草动物Gourmet Grazers （贪心，二分，数据结构优化）

贪心

考场上因无优化与卡常T掉的\(n \log(n)\)

//#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 = 100007;

struct Day{

	long long cost, taste;

	bool operator < (const Day &com) const{

		if(taste != com.taste) return taste > com.taste;

		return cost > com.cost;

	}

}day[N];

struct Food{

	long long cost, taste;

	bool operator < (const Food &com) const{

		if(cost != com.cost) return cost < com.cost;

		return taste < com.taste;

	}

}food[N];

int n, m;

inline int FindFood(int price){

	int l = 1, r = m;

	while(l <= r){

		int mid = (l + r) >> 1;

		if(food[mid].cost >= price)

			r = mid - 1;

		else

			l = mid + 1;

	}

	return l;

}

int vis[N];

int main(){

freopen("snack.in", "r", stdin);

freopen("snack.out", "w", stdout);

	io >> n >> m;

	R(i,1,n){

		io >> day[i].cost >> day[i].taste;

	}

	R(i,1,m){

		io >> food[i].cost >> food[i].taste;

	}

	if(m < n){

		printf("-1");

		return 0;

	}

	sort(day + 1, day + n + 1);

	sort(food + 1, food + m + 1);

	long long ans = 0;

	R(i,1,n){

		int pos = FindFood(day[i].cost);

		while(vis[pos] == true) ++pos;

		if(pos > m){

			printf("-1"); return 0;

		}

		int flag = 0;

		R(j,pos,m){

			if(vis[j]) continue;

			if(food[j].taste >= day[i].taste){

				vis[j] = true;

				ans += food[j].cost;

				flag = 1;

				break;

			}

		}

		if(!flag){

			printf("-1"); return 0;

		}

	}

	printf("%lld", ans);

	return 0;

}

/*

one money raise

one taste down

4 7

1 1

2 3

1 4

4 2

3 2

2 1

4 3

5 2

5 4

2 6

4 4

*/

正解用数据结构，或STL水

#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;

#include <set>

const int N = 100007;

multiset<int> st;

pair<int,int> day[N], food[N];

int main(){

//FileOpen();

    int n,m;

    io >> n >> m;

    R(i,1,n){

    	io >> day[i].second >> day[i].first;

    }

    R(i,1,m){

    	io >> food[i].second >> food[i].first;

    }

    sort(day + 1, day + n + 1);

    sort(food + 1, food + m + 1);

    int j = m;

    long long ans = 0;

    nR(i,n,1){

        while(j && food[j].first >= day[i].first){

        	st.insert(food[j].second);

			--j;

        }

        multiset<int>::iterator it = st.lower_bound(day[i].second);

        if(it == st.end()){

            printf("-1"); return 0;

        }

        ans += *it;

        st.erase(it);

    }

    printf("%lld", ans);

    return 0;

}

巴特西

Luogu2869 [USACO07DEC]美食的食草动物Gourmet Grazers （贪心，二分，数据结构优化）

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