10.25考试

T1
交换相邻两项贪心，然后推式子即可；

#include<iostream>
#include<cstdio>
#include<algorithm>
using namespace std;
const int N=1e5+7;
struct node{
	int a,t;
}b[N];
int n;
double v,sum1,sum2;
int cmp(node x,node y){
	return x.a>y.a;
}
int main(){
	freopen("physics.in","r",stdin);
	freopen("physics.out","w",stdout);
	scanf("%d",&n);
	for(int i=1;i<=n;i++){
		scanf("%d%d",&b[i].a,&b[i].t);
		sum1+=1.0*v*b[i].t+1.0*1/2*b[i].a*b[i].t*b[i].t;
		v+=b[i].a*b[i].t;
	}
	sort(b+1,b+n+1,cmp);
	v=0;
	for(int i=1;i<=n;i++){
		sum2+=1.0*v*b[i].t+1.0*1/2*b[i].a*b[i].t*b[i].t;
		v+=b[i].a*b[i].t;
	}
//	cout<<v<<"\n";
//	cout<<sum1<<" "<<sum2<<"\n";
	printf("%.1lf",sum2-sum1);
	fclose(stdin);
	fclose(stdout);
	return 0;
}
/*
2
2 1
30 2
*/

T2
每次找包括自己的前h个数中，最小的那个数就是答案；
用单调队列维护；

#include<iostream>
#include<cstdio>
using namespace std;
const int N=1e5+7;
int n,h,b,e,l,r;
int c[N],ans[N],q[N];
void init(){
	for(int i=1;i<=n;i++){
		ans[i]=0;
	}
}
int main(){
	freopen("coffee.in","r",stdin);
	freopen("coffee.out","w",stdout);
	while(scanf("%d%d%d%d",&n,&h,&b,&e)!=EOF){
		init();
		for(int i=1;i<=n;i++){
			scanf("%d",&c[i]);
		}
		l=1,r=0;
		for(int i=1;i<=n;i++){
			while(l<=r&&i-q[l]>=h) l++;
			while(l<=r&&c[q[r]]>=c[i]) r--;
			q[++r]=i;
			ans[q[l]]++;
		}
		for(int i=b;i<=e;i++){
			cout<<ans[i]<<" ";
		}
		cout<<"\n";
	}
	fclose(stdin);
	fclose(stdout);
	return 0;
}
/*
6 3 1 6
5 4 4 3 5 6
3 3 2 3 
9000 9000 9000
*/