867. 转置矩阵
class Solution {
public int[][] transpose(int[][] matrix) {
int m=matrix.length;
int n=matrix[0].length;
int[][] res=new int[n][m];
int k=0;
for(int i=0;i<m;i++){
for(int j=0;j<n;j++){
res[j][i]=matrix[i][j];
}
}
return res;
}
}
1572. 矩阵对角线元素的和
class Solution {
public int diagonalSum(int[][] mat) {
int n = mat.length;
int res = 0;
for(int i = 0; i < n; i++){
res += mat[i][i];
res += mat[i][n-i-1];
}
if((n&1) == 0) return res;
return res-mat[n/2][n/2];
}
}
