38 lines
718 B
C
38 lines
718 B
C
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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void itoar(char *s, int x);
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/* converts first arg to int, puts it to output with itoar */
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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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int x = atoi(argv[1]);
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char s[strlen(argv[1])+1];
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itoar(s, x);
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printf("%s\n", s);
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return 0;
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}
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char * utoar(char *s, unsigned x);
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/* itoa: writes int x to string s in decimal
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* recursive implementation */
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void itoar(char *s, int x)
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{
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unsigned y = (x < 0) ? *(s++) = '-', -x : x;
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s = utoar(s, y);
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*s = '\0';
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}
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/* utoar: helper for itoa */
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char * utoar(char *s, unsigned x)
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{
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if (x / 10)
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s = utoar(s, x / 10);
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*s = x % 10 + '0';
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return s+1;
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}
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