Want to solve Find Total Power Amazon OA 2023?, if yes then this article is for you.
We have research and collected a bundle of questions which was asked in Amazon OA in the year of 2022 and 2023. Today, we are going to see another problem from amazon oa called Find Total Power which was asked in 2022, this questions might be still active in some of the Amazon OA so save all the solutions and lets see how can we solve this problem.
Contents
Find Total Power Amazon OA 2023 Solution
As the ruler of a kingdom, you have an army of wizards at your command.
You are given a 0-indexed integer array strength
, where strength[i]
denotes the strength of the ith
wizard. For a contiguous group of wizards (i.e. the wizards’ strengths form a subarray of strength
), the total strength is defined as the product of the following two values:
- The strength of the weakest wizard in the group.
- The total of all the individual strengths of the wizards in the group.
Return the sum of the total strengths of all contiguous groups of wizards. Since the answer may be very large, return it modulo 109 + 7
.
A subarray is a contiguous non-empty sequence of elements within an array.
Example 1:
Input: strength = [1,3,1,2]
Output: 44
Explanation:
The following are all the contiguous groups of wizards:
- [1] from [1,3,1,2] has a total strength of min([1]) * sum([1]) = 1 * 1 = 1
- [3] from [1,3,1,2] has a total strength of min([3]) * sum([3]) = 3 * 3 = 9
- [1] from [1,3,1,2] has a total strength of min([1]) * sum([1]) = 1 * 1 = 1
- [2] from [1,3,1,2] has a total strength of min([2]) * sum([2]) = 2 * 2 = 4
- [1,3] from [1,3,1,2] has a total strength of min([1,3]) * sum([1,3]) = 1 * 4 = 4
- [3,1] from [1,3,1,2] has a total strength of min([3,1]) * sum([3,1]) = 1 * 4 = 4
- [1,2] from [1,3,1,2] has a total strength of min([1,2]) * sum([1,2]) = 1 * 3 = 3
- [1,3,1] from [1,3,1,2] has a total strength of min([1,3,1]) * sum([1,3,1]) = 1 * 5 = 5
- [3,1,2] from [1,3,1,2] has a total strength of min([3,1,2]) * sum([3,1,2]) = 1 * 6 = 6
- [1,3,1,2] from [1,3,1,2] has a total strength of min([1,3,1,2]) * sum([1,3,1,2]) = 1 * 7 = 7
The sum of all the total strengths is 1 + 9 + 1 + 4 + 4 + 4 + 3 + 5 + 6 + 7 = 44.
Example 2:
Input: strength = [5,4,6]
Output: 213
Explanation:
The following are all the contiguous groups of wizards:
- [5] from [5,4,6] has a total strength of min([5]) * sum([5]) = 5 * 5 = 25
- [4] from [5,4,6] has a total strength of min([4]) * sum([4]) = 4 * 4 = 16
- [6] from [5,4,6] has a total strength of min([6]) * sum([6]) = 6 * 6 = 36
- [5,4] from [5,4,6] has a total strength of min([5,4]) * sum([5,4]) = 4 * 9 = 36
- [4,6] from [5,4,6] has a total strength of min([4,6]) * sum([4,6]) = 4 * 10 = 40
- [5,4,6] from [5,4,6] has a total strength of min([5,4,6]) * sum([5,4,6]) = 4 * 15 = 60
The sum of all the total strengths is 25 + 16 + 36 + 36 + 40 + 60 = 213.
Constraints:
1 <= strength.length <= 105
1 <= strength[i] <= 109
Related: Google Online Assessment 2022 Questions List

SOLUTION
Program: Find Total Power Amazon OA Solution in Python
class Solution:
def totalStrength(self, A: List[int]) -> int:
N = len(A)
Q = int(1e9)+7
# monostack
# ple[i] = previous lesser element, than the one at i
st, ple = [], [-1]*N
for i in range(N-1,-1,-1):
while st and A[st[-1]] > A[i]:
ple[st.pop()] = i
st += [i]
# preprocessing
ps = [0] * (N+1) # suffix sum
ds = [0] * (N+1) # suffix sum of suffix sum
dpM = [0] * (N+1) # dpM[i] = sum( suffixMin of A[0..i] )
for z in range(N):
i, j = ~z-1, ~z
ps[i] = A[j] + ps[j]
ds[i] = ps[i] + ds[j]
k = ple[z]
dpM[z] = A[z] * (z-k)
if k != -1: dpM[z] += dpM[k]
def query(L, R): # -> sum( sum(A[k..R]) for k in [L..R] )
if R < L: return 0
diff = ds[L] - ds[R+1]
chop = ps[R+1]
size = R-L+1
return diff - chop * size
ans = 0
dpC = [0] * (N+1)
for i in range(N):
j = ple[i]
x = A[i] * query(j+1, i) % Q
if j == -1: y = 0
else:
s = ps[j+1] - ps[i+1]
y = (dpC[j] + dpM[j] * s) % Q
dpC[i] = (x + y) % Q
ans = (ans + dpC[i]) % Q
return ans
Program: Find Total Power Amazon OA Solution in Java
public int totalStrength(int[] A) {
int res = 0, ac = 0, mod = (int)1e9 + 7, n = A.length;
Stack<Integer> stack = new Stack<>();
int[] acc = new int[n + 2];
for (int r = 0; r <= n; ++r) {
int a = r < n ? A[r] : 0;
ac = (ac + a) % mod;
acc[r + 1] = (ac + acc[r]) % mod;
while (!stack.isEmpty() && A[stack.peek()] > a) {
int i = stack.pop();
int l = stack.isEmpty() ? -1 : stack.peek();
long lacc = l < 0 ? acc[i] : acc[i] - acc[l], racc = acc[r] - acc[i];
int ln = i - l, rn = r - i;
res = (int)(res + (racc * ln - lacc * rn) % mod * A[i] % mod) % mod;
}
stack.push(r);
}
return (res + mod) % mod;
}
Program: Find Total Power Amazon OA Solution in C++
int totalStrength(vector<int>& A) {
int res = 0, ac = 0, mod = 1e9 + 7, n = A.size();
vector<int> stack = {}, acc(n + 2);
for (int r = 0; r <= n; ++r) {
int a = r < n ? A[r] : 0;
ac = (ac + a) % mod;
acc[r + 1] = (ac + acc[r]) % mod;
while (!stack.empty() && A[stack.back()] > a) {
int i = stack.back(); stack.pop_back();
int l = stack.empty() ? -1 : stack.back();
long lacc = l < 0 ? acc[i] : acc[i] - acc[l], racc = acc[r] - acc[i];
int ln = i - l, rn = r - i;
res = (res + (racc * ln - lacc * rn) % mod * A[i] % mod) % mod;
}
stack.push_back(r);
}
return (res + mod) % mod;
}
Amazon OA 2023 Questions with Solution
- Shopping Patterns Solution Amazon OA 2023
- Reorder Data in Log Files Solution Amazon OA 2023
- Top K Frequent Words Solution Amazon OA 2023
- Trees Height Solution Amazon OA SDE 2023
- Counting Binary Substrings Amazon OA 2023
- Grid Connections Amazon OA 2023
- Shipment Imbalance Amazon OA 2023
- Max Profit Amazon OA 2023
- Find Lowest Price Amazon OA 2023
- Decode String Frequency Amazon OA 2023
- Simple Cipher Amazon OA 2023
- Valid Discount Coupons Amazon OA 2023 Solution
- Count Maximum Teams Amazon OA 2023
- Minimum Coin Flips Amazon OA 2023
- Max Average Stock Price Amazon OA 2023 Solution
- Robot Bounded In Circle Amazon OA 2023
- Shopping Options Amazon OA 2023 Solution
- Fill The Truck Maximum Units on a Truck Amazon OA Solution
- Maximize Score After N Operations Number Game Solution Amazon OA 2023
- Slowest Key Amazon OA 2023 Solution
- Five Star Seller Maximum Average Pass Ratio Amazon OA 2023
- Split String Into Unique Primes Amazon OA 2023 Solution
- Storage Optimization Amazon OA 2023 Solution
- Minimum Difficulty of a Job Schedule Amazon OA 2023 Solution
- Autoscale Policy Utilization Check Amazon OA 2023
- Optimal Utilization Solution Amazon OA 2023
- Merge Two Sorted Lists Solution Amazon OA 2023
- Two Sum Unique Pairs Solution Amazon OA 2023
- Amazon Music Pairs Amazon OA 2023 Solution
- Class Grouping Amazon OA 2023 Solution
- Find Max products Amazon OA 2023 Solution
- Get encrypted number Amazon OA 2023 Solution
- Find Total Imbalance Amazon OA 2023 Solution