这两段区间包括2在内的所有subarray的最小值都是2,其分别可以组成的subarry的个数是 len([3])和len([4,5]),左右区间合并在一起可以组成的subarray的个数是len([3])*len([4,5]),再加上2本身自己组成一个独立的subarray [2],其总数就是 len([3]) + len([4,5]) + len([3])*len([4,5]) ...
package leetcode // 解法一 最快的解是 DP + 单调栈 func sumSubarrayMins(A []int) int { stack, dp, res, mod := []int{}, make([]int, len(A)+1), 0, 1000000007 stack = append(stack, -1) for i := 0; i < len(A); i++ { for stack[len(stack)-1] != -1 && A[i]...
It is likely that we'll consider the O(n^2) solution optimal since we are adding O(n^2) numbers. But if we jump out of the box of "adding number one at a time", we'll see a O(n) solution. For each array element A[i], if we can find out how many subarrays have it as...
Github 同步地址: https://github.com/grandyang/leetcode/issues/907 参考资料: https://leetcode.com/problems/sum-of-subarray-minimums/ https://leetcode.com/problems/sum-of-subarray-minimums/discuss/170857/One-stack-solution https://leetcode.com/problems/sum-of-subarray-minimums/discuss/222895/Ja...
https://leetcode.com/problems/sum-of-subarray-minimums/discuss/178876/stack-solution-with-very-detailed-explanation-step-by-step classSolution {publicintsumSubarrayMins(int[] A) {intlen =A.length; Stack<Integer> stack =newStack<>();int[] left =newint[len];int[] right =newint[len];for...
1classSolution {2func sumSubarrayMins(_ A: [Int]) ->Int {3varstack:[Int] =[Int]()4varn:Int =A.count5varres:Int =06varmod:Int = Int(1e9 +7)7varj:Int =08vark:Int =09foriin0...n10{11while(!stack.isEmpty && A[stack.last!] > (i == n ?0: A[i]))12{13j =stack.re...
Can you solve this real interview question? Sum of Subarray Minimums - Given an array of integers arr, find the sum of min(b), where b ranges over every (contiguous) subarray of arr. Since the answer may be large, return the answer modulo 109 + 7. Ex
907. Sum of Subarray Minimums Given an array of integers A, find the sum of min(B), where B ranges over every (contiguous) subarray of A. Since the answer may be large, return the answer modulo 10^9 + 7.Example 1: Input: [3,1,2,4] Output: 17 Explanation: Subarrays are [3]...
907. Sum of Subarray Minimums Given an array of integers A, find the sum of min(B), where B ranges over every (contiguous) subarray of A. Since the answer may be large, return the answer modulo 10^9 + 7....
Given an array of integers arr, find the sum of min(b), where b ranges over every (contiguous) subarray of arr. Since the answer may be large, return the answer modulo 10**9 + 7. Example 1: Input: arr = [3,1,2,4] Output: 17 Explanation: Subarrays are [3], [1], [2], ...