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authorjack <[email protected]>2024-06-14 13:13:15 -0600
committerjack <[email protected]>2024-06-14 13:13:15 -0600
commitd343a3b18dbaca9297d4f7b2280c4a16f0a5c8aa (patch)
tree96df922dae2a5073d9a50ea70c7aae6aa37e3ebe /matrix_diagonal_sum.cpp
downloadleetcode-d343a3b18dbaca9297d4f7b2280c4a16f0a5c8aa.tar.gz
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+// 1572. Matrix Diagonal Sum
+#include "leetcode.h"
+
+/*
+ * given a square matrix 'mat', return the sum of the matrix
+ * diagonals. only include the sum of all the elements on the
+ * primary diagonal and all the elements on the secondary
+ * diagonal that are not part of the primary
+ */
+
+class Solution {
+public:
+ int diagonalSum(vvd(int) & mat) {
+ int n = mat.size(), ans = 0;
+ for (int i = 0; i < n; i++) {
+ if (i != n - i - 1)
+ ans += mat[i][i] + mat[i][n - i - 1];
+ else
+ ans += mat[i][i];
+ }
+ return ans;
+ }
+};
+
+int main() {
+ Solution obj;
+ vvd(int) m1 = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};
+ vvd(int) m2 = {{1, 1, 1, 1}, {1, 1, 1, 1}, {1, 1, 1, 1}, {1, 1, 1, 1}};
+ vvd(int) m3 = {{5}};
+ printf("%d\n", obj.diagonalSum(m1)); // expect: 25
+ printf("%d\n", obj.diagonalSum(m2)); // expect: 8
+ printf("%d\n", obj.diagonalSum(m3)); // expect: 5
+}