PTA 7-2 Summation and Counting of Diagonal Elements of Square Matrices Solution

For an input square matrix of N*N, find the sum of the elements on the two diagonals and the number of non-zero elements.

input format:

Enter a positive integer N not exceeding 20 in the first line,
In the next N lines, enter the N of each line of the square matrix in turn.code>N elements, the elements of the square matrix are integers whose absolute value does not exceed 1000, separated by spaces.

Output format:

Output the sum of the elements on the two diagonals of the square matrix and the number of non-zero elements in the format sum = , count = . in one line, where and represent the sum of elements and number of non-zero elements respectively, and are replaced with the actual number when outputting.
Tips: (1) The intersecting elements of the two diagonals are not repeatedly calculated; (2) The output is strictly in the specified format, and characters such as spaces and line breaks are not allowed to be added or deleted at will.

Input Sample 1:

41 2 3 41 2 3 40 1 2 30 1 2 3

Example output 1:

sum = 16, count = 7.

Input Sample 2:

51 2 3 2 11 2 3 2 11 2 3 2 11 2 3 2 11 2 3 2 1

Example output:

sum = 15, count = 9.

topic analysis

1. The title requires to calculate the sum of the main diagonal elements, and requires no repetition; requires to calculate the number of non-zero elements (on the diagonal)

2. Diagonal element coordinate feature - Main diagonal element-i=j——Subdiagonal element feature-i=n-1-j

3. Special requirements: Do not add or delete characters such as spaces, newlines, etc. at will; Diagonal cross-repetitive elements cannot be counted repeatedly

#include #define N 21int main(){int a[N][N];int n,i,j;int sum=0,count=0;scanf("%d",&n);for(i=0;i