JAVA /C++ Easiest Solution Ever...
class Solution {\n    public int diagonalSum(int[][] mat) {\n        int sum=0;\n        \n        for(int i=0;i<mat.length;i++){\n            sum+=mat[i][i];\n
class Solution {\n    public int diagonalSum(int[][] mat) {\n        int sum=0;\n        \n        for(int i=0;i<mat.length;i++){\n            sum+=mat[i][i];\n            if(i!=mat.length-i-1){\n                sum+=mat[i][mat.length-1-i];\n            }\n            \n        }\n        return sum;\n    }\n}
['C', 'Java']