diff options
| -rw-r--r-- | 0008/main.c | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/0008/main.c b/0008/main.c new file mode 100644 index 0000000..c229dd7 --- /dev/null +++ b/0008/main.c @@ -0,0 +1,58 @@ +#include <ctype.h> +#include <stdint.h> +#include <stdio.h> + +char * skip_space(char *s) { + while (isspace(*s)) s++; + return s; +} + +int symbol(char **ps) { + char *s = *ps; + if (*s == '+') { + s++; + *ps = s; + return 1; + } + if (*s == '-') { + s++; + *ps = s; + return -1; + } + return 1; +} + +int64_t read_num(char *s) { + int64_t r = 0; + int i = 0; + while (1) { + if (s[i] < '0' || s[i] > '9') { + return r; + } + r = r * 10 + s[i] - '0'; + if (r > ((int64_t)1 << 32)) { + return r; + } + i++; + } + return r; +} + +int myAtoi(char* s) { + s = skip_space(s); + int sym = symbol(&s); + int64_t r = read_num(s); + if (sym > 0) { + if (r > 2147483647) r = 2147483647; + } else { + if (r > 2147483648) r = 2147483648; + } + return sym > 0 ? r : -r; +} + +int main() { + printf("%d\n", myAtoi("123")); + printf("%d\n", myAtoi(" +123")); + printf("%d\n", myAtoi("0000000000012345678")); + printf("%d\n", myAtoi("-123111111111111111")); +}
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