mirror of https://github.com/TheAlgorithms/C
45 lines
842 B
C
45 lines
842 B
C
/*
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* convert from any base to decimal
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*/
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#include <ctype.h>
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#include <stdio.h>
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int main(void)
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{
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int base, i, j;
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char number[100];
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unsigned long decimal = 0;
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printf("Enter the base: ");
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scanf("%d", &base);
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printf("Enter the number: ");
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scanf("%s", &number[0]);
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for (i = 0; number[i] != '\0'; i++)
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{
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if (isdigit(number[i]))
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number[i] -= '0';
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else if (isupper(number[i]))
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number[i] -= 'A' - 10;
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else if (islower(number[i]))
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number[i] -= 'a' - 10;
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else
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number[i] = base + 1;
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if (number[i] >= base)
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{
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printf("invalid number\n");
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return 0;
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}
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}
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for (j = 0; j < i; j++)
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{
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decimal *= base;
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decimal += number[j];
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}
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printf("%lu\n", decimal);
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}
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