Sum the main diagonal of an n×n matrix m:

for (int i = 0; i < n; i++) sum += m[i][i]; Main diagonal = m[0][0], m[1][1], ..., m[n-1][n-1].

for (int i = 0; i < n; i++) sum += m[i][n-i];

for (int i = 0; i < n; i++) sum += m[i][i];

Traversing 2D Arrays

AP Computer Science A· difficulty 4/5

Sum the main diagonal of an n\timesn matrix m:

Explanation

Main diagonal = m[0][0], m[1][1], ..., m[n-1][n-1].

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