leetcode-daily/cpp/2203/220306-CN.cpp

36 lines
1.6 KiB
C++

#include <vector>
#include <iostream>
/**
* 2100. Find Good Days to Rob the Bank
* You and a gang of thieves are planning on robbing a bank. You are given a 0-indexed integer array security, where security[i] is the number of guards on duty on the ith day. The days are numbered starting from 0. You are also given an integer time.
* The ith day is a good day to rob the bank if:
* There are at least time days before and after the ith day,
* The number of guards at the bank for the time days before i are non-increasing, and
* The number of guards at the bank for the time days after i are non-decreasing.
* More formally, this means day i is a good day to rob the bank if and only if security[i - time] >= security[i - time + 1] >= ... >= security[i] <= ... <= security[i + time - 1] <= security[i + time].
* Return a list of all days (0-indexed) that are good days to rob the bank. The order that the days are returned in does not matter.
*/
class Solution {
public:
static std::vector<int> goodDaysToRobBank(const std::vector<int>& security, int time) {
int n = security.size();
std::vector<int> ret, isNotIncreasingSince(n), isNotDecreasingSince(n);
for (int i = 1; i < n; ++i) {
isNotDecreasingSince[i] = (security[i - 1] <= security[i]) ? isNotDecreasingSince[i - 1] : i;
isNotIncreasingSince[i] = (security[i - 1] >= security[i]) ? isNotIncreasingSince[i - 1] : i;
}
for (int i = time; i < n - time; ++i)
if (isNotIncreasingSince[i] <= i - time && isNotDecreasingSince[i + time] <= i)
ret.push_back(i);
return ret;
}
};
int main() {
auto ret = Solution::goodDaysToRobBank({1,2,3,4,5,6},2);
for (int i : ret)
std::cout << i << ' ';
}