diff --git a/README.md b/README.md index c7d59b5a9..e4891e410 100644 --- a/README.md +++ b/README.md @@ -61,6 +61,7 @@ LeetCode |1733|[Minimum Number of People to Teach](https://leetcode.com/problems/minimum-number-of-people-to-teach/) | [C++](./algorithms/cpp/minimumNumberOfPeopleToTeach/MinimumNumberOfPeopleToTeach.cpp)|Medium| |1732|[Find the Highest Altitude](https://leetcode.com/problems/find-the-highest-altitude/) | [C++](./algorithms/cpp/findTheHighestAltitude/FindTheHighestAltitude.cpp)|Easy| |1725|[Number Of Rectangles That Can Form The Largest Square](https://leetcode.com/problems/number-of-rectangles-that-can-form-the-largest-square/) | [C++](./algorithms/cpp/numberOfRectanglesThatCanFormTheLargestSquare/NumberOfRectanglesThatCanFormTheLargestSquare.cpp)|Easy| +|1716|[Calculate Money in Leetcode Bank](https://leetcode.com/problems/calculate-money-in-leetcode-bank/) | [C++](./algorithms/cpp/calculateMoneyInLeetcodeBank/CalculateMoneyInLeetcodeBank.cpp)|Easy| |1625|[Lexicographically Smallest String After Applying Operations](https://leetcode.com/problems/lexicographically-smallest-string-after-applying-operations/) | [C++](./algorithms/cpp/lexicographicallySmallestStringAfterApplyingOperations/LexicographicallySmallestStringAfterApplyingOperations.cpp)|Medium| |1624|[Largest Substring Between Two Equal Characters](https://leetcode.com/problems/largest-substring-between-two-equal-characters/) | [C++](./algorithms/cpp/largestSubstringBetweenTwoEqualCharacters/LargestSubstringBetweenTwoEqualCharacters.cpp)|Easy| |1605|[Find Valid Matrix Given Row and Column Sums](https://leetcode.com/problems/find-valid-matrix-given-row-and-column-sums/) | [C++](./algorithms/cpp/FindValidMatrixGivenRowAndColumnSums/FindValidMatrixGivenRowAndColumnSums.cpp)|Medium| diff --git a/algorithms/cpp/calculateMoneyInLeetcodeBank/CalculateMoneyInLeetcodeBank.cpp b/algorithms/cpp/calculateMoneyInLeetcodeBank/CalculateMoneyInLeetcodeBank.cpp new file mode 100644 index 000000000..48f974463 --- /dev/null +++ b/algorithms/cpp/calculateMoneyInLeetcodeBank/CalculateMoneyInLeetcodeBank.cpp @@ -0,0 +1,67 @@ +// Source : https://leetcode.com/problems/calculate-money-in-leetcode-bank/ +// Author : Hao Chen +// Date : 2021-03-28 + +/***************************************************************************************************** + * + * Hercy wants to save money for his first car. He puts money in the Leetcode bank every day. + * + * He starts by putting in $1 on Monday, the first day. Every day from Tuesday to Sunday, he will put + * in $1 more than the day before. On every subsequent Monday, he will put in $1 more than the + * previous Monday. + * + * Given n, return the total amount of money he will have in the Leetcode bank at the end of the n^th + * day. + * + * Example 1: + * + * Input: n = 4 + * Output: 10 + * Explanation: After the 4^th day, the total is 1 + 2 + 3 + 4 = 10. + * + * Example 2: + * + * Input: n = 10 + * Output: 37 + * Explanation: After the 10^th day, the total is (1 + 2 + 3 + 4 + 5 + 6 + 7) + (2 + 3 + 4) = 37. + * Notice that on the 2^nd Monday, Hercy only puts in $2. + * + * Example 3: + * + * Input: n = 20 + * Output: 96 + * Explanation: After the 20^th day, the total is (1 + 2 + 3 + 4 + 5 + 6 + 7) + (2 + 3 + 4 + 5 + 6 + 7 + * + 8) + (3 + 4 + 5 + 6 + 7 + 8) = 96. + * + * Constraints: + * + * 1 <= n <= 1000 + ******************************************************************************************************/ + +class Solution { +public: + int totalMoney(int n) { + int weeks = n / 7; + int days = n % 7; + + int m = 1 + 2 + 3 + 4 + 5 + 6 + 7; + // we know + // week1 = 0*7 + m + // week2 = 1*7 + m + // week3 = 2*7 + m + // weekn = (n-1)*7 + m + // So, + // week1 + week2 + week3 + ....+ weekn + // = n*m + 7*(0+1+2+..n-1) + // = n*m + 7*(n-1)*n/2 + + int money = weeks*m + 7 * (weeks-1) * weeks / 2; + + // for the rest days + // every day needs to add previous `weeks * 1`, it is days* weeks + // then add from 1 to days + money += (days*weeks + days*(days+1)/2); + + return money; + } +};