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《洛谷P2659 美麗的序列》

算下作為最小值的最大長度,然後找下最大的。

// Author: levil
#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
typedef pair<int,int> pii;
const int N = 2e6+5;
const int M = 1e6+5;
const LL Mod = 1e9+7;
#define rg register
#define pi acos(-1)
#define INF 1e9
#define CT0 cin.tie(0),cout.tie(0)
#define
IO ios::sync_with_stdio(false) #define dbg(ax) cout << "now this num is " << ax << endl; namespace FASTIO{ inline LL read(){ LL x = 0,f = 1;char c = getchar(); while(c < '0' || c > '9'){if(c == '-') f = -1;c = getchar();} while(c >= '0' && c <= '
9'){x = (x<<1)+(x<<3)+(c^48);c = getchar();} return x*f; } void print(int x){ if(x < 0){x = -x;putchar('-');} if(x > 9) print(x/10); putchar(x%10+'0'); } } using namespace FASTIO; void FRE(){/*freopen("data1.in","r",stdin); freopen("data1.out","w",stdout);
*/} int a[N],L[N],r[N],S[N]; int main() { int n;n = read(); for(rg int i = 1;i <= n;++i) a[i] = read(); int top = 0; S[++top] = 0; a[0] = -1,a[n+1] = -1; for(rg int i = 1;i <= n+1;++i) { while(top != 0 && a[i] < a[S[top]]) { r[S[top]] = i; L[S[top]] = S[top-1]; top--; } S[++top] = i; } LL ans = -1; for(rg int i = 1;i <= n;++i) { ans = max(ans,1LL*a[i]*(r[i]-L[i]-1)); } printf("%lld\n",ans); // system("pause"); }
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