1 #include <cstdio> 2 #include <iostream> 3 #define LL long long 4  5 const int MAXN = 2000002; 6 int n, t; 7 LL ans, a[MAXN], s[MAXN], l[MAXN], r[MAXN]; 8  9 inline int read()10 {11     int x = 0, f = 1;12     char ch = getchar();13     for(; !isdigit(ch); ch = getchar()) if(ch == ‘-‘) f = -1;14     for(; isdigit(ch); ch = getchar()) x = (x << 1) + (x << 3) + ch - ‘0‘;15     return x * f;16 }17 18 inline LL max(LL x, LL y)19 {20     return x > y ? x : y;21 }22 23 int main()24 {25     int i;26     n = read();27     for(i = 1; i <= n; i++) a[i] = read();28     a[0] = a[n + 1] = -1;29     for(i = 1; i <= n + 1; i++)30     {31         while(t && a[s[t]] > a[i]) r[s[t--]] = i;32         s[++t] = i;33     }34     t = 0;35     for(i = n; i >= 0; i--)36     {37         while(t && a[s[t]] > a[i]) l[s[t--]] = i;38         s[++t] = i;39     }40     for(i = 1; i <= n; i++) ans = max(ans, a[i] * (r[i] - l[i] - 1));41     printf("%lld\n", ans);42     return 0;43 }