Calculate Money in Leetcode Bank

🏠 ⬅️ ➡️

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 nth day.

Example 1:

Input: n = 4 Output: 10 Explanation: After the 4th day, the total is 1 + 2 + 3 + 4 = 10.

Example 2:

Input: n = 10 Output: 37 Explanation: After the 10th day, the total is (1 + 2 + 3 + 4 + 5 + 6 + 7) + (2 + 3 + 4) = 37. Notice that on the 2nd Monday, Hercy only puts in $2.

Example 3:

Input: n = 20 Output: 96 Explanation: After the 20th 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

Note: This problem is from LeetCode.
Compiled
Executed
Correct
program main
    implicit none

    integer :: n, i, j
    integer :: days(7), prev_days(7)
    integer :: total

    do while (.true.)
        read(*,*) n
        if (n == -1) exit

        ! Initialize the array with the starting values
        days = (/1, 1, 1, 1, 1, 1, 1/)

        ! Loop through the days
        do i=2,n
            ! If it's a Monday, add one to the previous Monday's value
            if (mod(i,7) == 1) then
                days(1) = days(1) + 1
            else
                ! Otherwise, add one to the previous day's value
                days(mod(i-1,7)+1) = days(mod(i-1,7)+1) + 1
            end if
        end do

        ! Print the total
        write(*,'(I0)') sum(days)
    end do

end program main
Compiled
Executed
Correct
PROGRAM LeetcodeBank
      IMPLICIT NONE

      INTEGER :: n, i, j, total

      READ(*,*) n

      total = 0

      DO i = 1, n
          IF (MODULO(i, 7) == 1) THEN
              total = total + i
          ELSE
              total = total + (i - 1)
          END IF
      END DO

      WRITE(*,*) total

      END PROGRAM LeetcodeBank
🌐 Data from online sources
def maxProductPath(grid):
    m, n, mod = len(grid), len(grid[0]), int(1e9 + 7)
    dp = [[[0, 0] for _ in range(n)] for _ in range(m)]

    dp[0][0] = [grid[0][0], grid[0][0]]

    for i in range(1, m):
        dp[i][0] = [dp[i - 1][0][0] * grid[i][0], dp[i - 1][0][0] * grid[i][0]]
    for j in range(1, n):
        dp[0][j] = [dp[0][j - 1][0] * grid[0][j], dp[0][j - 1][0] * grid[0][j]]

    for i in range(1, m):
        for j in range(1, n):
            if grid[i][j] < 0:
                dp[i][j][0] = min(dp[i - 1][j][1], dp[i][j - 1][1]) * grid[i][j]
                dp[i][j][1] = max(dp[i - 1][j][0], dp[i][j - 1][0]) * grid[i][j]
            else:
                dp[i][j][0] = max(dp[i - 1][j][0], dp[i][j - 1][0]) * grid[i][j]
                dp[i][j][1] = min(dp[i - 1][j][1], dp[i][j - 1][1]) * grid[i][j]

    return dp[m - 1][n - 1][0] % mod if dp[m - 1][n - 1][0] >= 0 else -1
The algorithm used is a dynamic programming approach, where we maintain a 3D DP array `dp` with dimensions m x n x 2. For each cell `dp[i][j]`, we store the maximum non-negative product and the minimum non-positive product of the path up until cell (i, j) in the grid. We initialize the first row and first column of the grid, and then iterate through the remaining cells.

At each cell, if the corresponding grid value is negative, the product of this value with the minimum non-positive value of the previous cells will give the maximum non-negative value for the current cell, and vice versa for minimum non-positive value. If the value is non-negative, multiplying by maximum non-negative values from previous cells will give the maximum non-negative value for the current cell, and similarly for minimum non-positive value.

After filling out the DP array, the result is the modulo of the maximum non-negative product of the last cell in the DP array, unless it's negative, in which case we return -1.

🌐 Data from online sources
#include <vector>
using namespace std;

int maxProductPath(vector<vector<int>>& grid) {
    int m = grid.size(), n = grid[0].size(), mod = 1e9 + 7;
    vector<vector<vector<long long>>> dp(m, vector<vector<long long>>(n, vector<long long>(2)));

    dp[0][0] = {grid[0][0], grid[0][0]};

    for(int i = 1; i < m; i++) {
        dp[i][0][0] = dp[i][0][1] = dp[i-1][0][0] * grid[i][0];
    }
    for(int j = 1; j < n; j++) {
        dp[0][j][0] = dp[0][j][1] = dp[0][j-1][0] * grid[0][j];
    }

    for(int i = 1; i < m; i++) {
        for(int j = 1; j < n; j++) {
            if(grid[i][j] < 0) {
                dp[i][j][0] = min(dp[i - 1][j][1], dp[i][j - 1][1]) * grid[i][j];
                dp[i][j][1] = max(dp[i - 1][j][0], dp[i][j - 1][0]) * grid[i][j];
            } else {
                dp[i][j][0] = max(dp[i - 1][j][0], dp[i][j - 1][0]) * grid[i][j];
                dp[i][j][1] = min(dp[i - 1][j][1], dp[i][j - 1][1]) * grid[i][j];
            }
        }
    }

    return dp[m - 1][n - 1][0] >= 0 ? dp[m - 1][n - 1][0] % mod : -1;
}
The algorithm used is a dynamic programming approach, where we maintain a 3D DP array `dp` with dimensions m x n x 2. For each cell `dp[i][j]`, we store the maximum non-negative product and the minimum non-positive product of the path up until cell (i, j) in the grid. We initialize the first row and first column of the grid, and then iterate through the remaining cells.

At each cell, if the corresponding grid value is negative, the product of this value with the minimum non-positive value of the previous cells will give the maximum non-negative value for the current cell, and vice versa for minimum non-positive value. If the value is non-negative, multiplying by maximum non-negative values from previous cells will give the maximum non-negative value for the current cell, and similarly for minimum non-positive value.

After filling out the DP array, the result is the modulo of the maximum non-negative product of the last cell in the DP array, unless it's negative, in which case we return -1.