29 lines
605 B
C
29 lines
605 B
C
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#include <stdio.h>
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int reverse(char string[], int i);
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/* reverses command line argument */
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int main(int argc, char *argv[])
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{
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if (argc < 2)
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return 1;
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printf("length : %d\n", reverse(argv[1], 0));
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printf("reversed : %s\n", argv[1]);
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return 0;
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}
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/* reverse: reverses string from index i, returns length
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* recursive implementation */
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int reverse(char s[], int i)
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{
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if (s[i] == '\0') { /* base case */
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return 0;
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}
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int j = reverse(s, i+1);
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if (j > i) { /* swap elements */
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char c;
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c = s[i], s[i] = s[j], s[j] = c;
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}
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return j+1;
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}
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