秋实大哥去打工

Time Limit: 1 Sec  Memory Limit: 256 MB

题目连接

http://acm.uestc.edu.cn/#/contest/show/59

Description

Input

Output

Sample Input

Sample Output

HINT

题意

题解：

初看这道题，啊好难啊

//qscqesze
#include <cstdio>
#include <cmath>
#include <cstring>
#include <ctime>
#include <iostream>
#include <algorithm>
#include <set>
#include <vector>
#include <sstream>
#include <queue>
#include <typeinfo>
#include <fstream>
#include <map>
#include <stack>
typedef long long ll;
using namespace std;
//freopen("D.in","r",stdin);
//freopen("D.out","w",stdout);
#define sspeed ios_base::sync_with_stdio(0);cin.tie(0)
#define maxn 200001
#define mod 10007
#define eps 1e-9
//const int inf=0x7fffffff;   //无限大
const int inf=0x3f3f3f3f;
/*
inline ll read()
{int x=0,f=1;char ch=getchar();while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}return x*f;
}
int buf[10];
inline void write(int i) {int p = 0;if(i == 0) p++;else while(i) {buf[p++] = i % 10;i /= 10;}for(int j = p-1; j >=0; j--) putchar('0' + buf[j]);printf("\n");
}
*/
//**************************************************************************************
using namespace std;
long long a[maxn],b[maxn],ans;
int r[maxn],l[maxn];
stack<int> s;
int main()
{int n;scanf("%d",&n);a[0]=a[n+1]=-1;for(int i=1;i<=n;i++){scanf("%d",&b[i]);b[i]+=b[i-1];scanf("%lld",&a[i]);}s.push(0);int p=0;for(int i=1;i<=n;i++){for(p=s.top();a[p]>=a[i];p=s.top())s.pop();l[i]=p+1;s.push(i);}while(!s.empty())s.pop();s.push(n+1);for(int i=n;i>0;i--){for(p=s.top();a[p]>=a[i];p=s.top())s.pop();r[i]=p-1;s.push(i);}for(int i=1;i<=n;i++)ans=max(ans,((b[r[i]]-b[i-1])+(b[i-1]-b[l[i]-1]))*a[i]);printf("%lld\n",ans);return 0;
}