41 lines
642 B
C
41 lines
642 B
C
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#include <stdio.h>
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#include <stdlib.h>
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typedef int T;
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#define FT "%d"
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int main(void) {
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T i = 1;
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long c_max = 0;
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for(;;) {
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T j = i;
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long c = 0;
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while (j != 1) {
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if (j % 2 == 1) {
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T j2 = j * 3 + 1;
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if ((j2 - 1) / 3 != j) {
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printf(FT " is not 3 * " FT " + 1 at starting point " FT, j2, j, i);
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exit(1);
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}
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j = j2;
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} else {
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j = j / 2;
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}
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c++;
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}
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if (c > c_max) {
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printf("new longest sequence starting at " FT ": %ld steps\n", i, c);
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c_max = c;
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}
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if (i + 1 > i) {
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i = i + 1;
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} else {
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printf(FT " is not greater than " FT "\n", i + 1, i);
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exit(1);
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}
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}
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}
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