leetcode

Leetcode submissions
git clone git://git.laack.co/leetcode.git
Log | Files | Refs | README

diagonal-sum.dart (871B)

      1 //Given a matrix return the sum of all the values in the
      2 //diagnols from top left to bottom right and top right to
      3 //bottom left. 
      4 //Ex.
      5 //1 2 3
      6 //3 4 5
      7 //2 4 5
      8 //The output would be 15 because you add up 1 + 4 + 5
      9 //and then add 3 + 2 onto that. Since 4 is the shared center
     10 //that will not be added on twice hence me zeroing it out in the 
     11 //code below.
     12 //The time complexity of this code is O(n) where n is the size of the matrix.
     13 //Time: 388ms Beats: 100%
     14 //Memory: 144.6MB Beats: 100%
     15 
     16 
     17 class Solution {
     18   int diagonalSum(List<List<int>> mat) {
     19       int total = 0;
     20       for(int i = 0 ; i < mat[0].length; ++i){
     21           total += mat[i][i];
     22           mat[i][i] = 0;
     23       }
     24       int count = 0;
     25       for(int i = mat[0].length - 1 ; i >= 0 ; --i){
     26         print(mat[count][i]);
     27         total += mat[count][i];
     28         count += 1;
     29       }
     30       return total;
     31   }
     32 }