60 lines
1.2 KiB
C
60 lines
1.2 KiB
C
/* Is $F:M\rightarrow M$ skew symmetric? */
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#include <stdio.h>
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char str[256];
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main()
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{
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double a[4][4];
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printf("is F:M->M skew-symmetric? yes if F has the form\n\n");
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printf(" 0 a d f\n\n");
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printf(" -a 0 b e\n\n");
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printf(" -d -b 0 c\n\n");
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printf(" f e c 0\n\n");
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printf("example:\n");
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printf(" 0 1 2 3\n");
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printf(" -1 0 4 5\n");
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printf(" -2 -4 0 6\n");
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printf(" 3 5 6 0\n\n");
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printf("row 1? ");
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scanf("%lg%lg%lg%lg", &a[0][0], &a[0][1], &a[0][2], &a[0][3]);
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printf("row 2? ");
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scanf("%lg%lg%lg%lg", &a[1][0], &a[1][1], &a[1][2], &a[1][3]);
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printf("row 3? ");
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scanf("%lg%lg%lg%lg", &a[2][0], &a[2][1], &a[2][2], &a[2][3]);
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printf("row 4? ");
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scanf("%lg%lg%lg%lg", &a[3][0], &a[3][1], &a[3][2], &a[3][3]);
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if (isskewsymmetric(a))
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printf("it is skew-symmetric\n");
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else
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printf("it is not skew-symmetric\n");
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}
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isskewsymmetric(a)
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double a[4][4];
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{
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if (
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a[0][0] == 0.0 &&
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a[1][1] == 0.0 &&
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a[2][2] == 0.0 &&
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a[3][3] == 0.0 &&
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a[0][1] == -a[1][0] &&
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a[0][2] == -a[2][0] &&
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a[1][2] == -a[2][1] &&
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a[0][3] == a[3][0] &&
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a[1][3] == a[3][1] &&
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a[2][3] == a[3][2])
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return 1;
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else
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return 0;
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}
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