26 lines
577 B
Plaintext
26 lines
577 B
Plaintext
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#include <stdlib.h>
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double** dmalloc_2d(int m, int n);
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void dfree_2d(double **A);
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// allocate a double-precision m x n matrix
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double** dmalloc_2d(int m, int n) {
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if (m <= 0 || n <= 0) return NULL;
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double **A = malloc(m * sizeof(double *));
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if (A == NULL) return NULL;
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A[0] = malloc(m*n*sizeof(double));
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if (A[0] == NULL) {
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free(A);
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return NULL;
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}
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for (int i = 1; i < m; i++)
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A[i] = A[0] + i * n;
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return A;
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}
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// de-allocating memory, allocated with dmalloc_2d
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void dfree_2d(double **A) {
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free(A[0]);
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free(A);
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}
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