It is the middle of 2018 and Maria Stepanovna, who lives outside Krasnokamensk (a town in Zabaikalsky region), wants to rent three displays to highlight an important problem.
There are nn displays placed along a road, and the ii-th of them can display a text with font size sisi only. Maria Stepanovna wants to rent such three displays with indices i<j<ki<j<k that the font size increases if you move along the road in a particular direction. Namely, the condition si<sj<sksi<sj<sk should be held.
The rent cost is for the ii-th display is cici. Please determine the smallest cost Maria Stepanovna should pay.
The first line contains a single integer nn (3≤n≤30003≤n≤3000) — the number of displays.
The second line contains nn integers s1,s2,…,sns1,s2,…,sn (1≤si≤1091≤si≤109) — the font sizes on the displays in the order they stand along the road.
The third line contains nn integers c1,c2,…,cnc1,c2,…,cn (1≤ci≤1081≤ci≤108) — the rent costs for each display.
If there are no three displays that satisfy the criteria, print -1. Otherwise print a single integer — the minimum total rent cost of three displays with indices i<j<ki<j<k such that si<sj<sksi<sj<sk.
5
2 4 5 4 10
40 30 20 10 40
90
3
100 101 100
2 4 5
-1
10
1 2 3 4 5 6 7 8 9 10
10 13 11 14 15 12 13 13 18 13
33
In the first example you can, for example, choose displays 11, 44 and 55, because s1<s4<s5s1<s4<s5 (2<4<102<4<10), and the rent cost is 40+10+40=9040+10+40=90.
In the second example you can't select a valid triple of indices, so the answer is -1.
#include <bits/stdc++.h> using namespace std; #define inf 0x3f3f3f3f const int maxn = 3e3+5; int a[maxn],b[maxn]; long long dp[maxn][10]; // dp[i][j]表示的是你现在再第i个之后你挑了第j个的时候的最小 值 //dp[i][j] = dp[k][j-1] + a[j]; int main() { int n; scanf("%d",&n); for(int i = 0 ; i < n ; i++) scanf("%d",&a[i]); for(int i = 0 ; i < n ; i++) scanf("%d",&b[i]); memset(dp,inf,sizeof(dp)); for(int i = 0 ; i < n ; i++) dp[i][0] = b[i]; // 初始话一下, 那么第i个数选0本书的时候的最小值为b[i] 0表示的是我已经选了一本书了 for(int k = 0 ; k < 3; k ++) { for(int i = 1 ; i < n ; i++) { for(int j = 0 ; j < i ; j++) { if(a[i] > a[j]) { dp[i][k] = min(dp[j][k-1]+b[i],dp[i][k]); } } } } long long ans = LLONG_MAX; for(int i = 0 ; i < n ; i++) { ans = min(ans,dp[i][2]); } if(ans > 3e8) ans = -1; printf("%d ",ans); }