Parse an integer

Turn a string like "-123" into the number -123, by hand — the job atoi does. Read an optional leading - to fix the sign, then build the value digit by digit: each new digit means result = result * 10 + digit. A character converts to its digit value with c - '0'.

Complete int parse_int(const char *s) that converts a string of digits (with an optional leading -) to its integer value, without using library functions like atoi.

/* Convert s (e.g. "-123") to its int value. Do not write main(). */
int parse_int(const char *s) {
    return 0;   /* change this */
}

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Parse an integer

Parse an integer

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