26 lines
504 B
C
26 lines
504 B
C
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// 设计函数int toInt(char *str), 实现将字符串转成数值的功能。 【提示】如 toInt("123") 返回 123
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#include <stdio.h>
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int toInt(char *str)
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{
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int n = 0;
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while (*str)
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{
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if (*str < '0' || *str > '9') // 先判断是否是数字
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{
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return -1;
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}
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n = n * 10 + *str - '0'; // 将字符转换为数字
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str++;
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}
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return n;
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}
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int main()
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{
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char *s = "123";
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int n = toInt(s);
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printf("%d\n", n);
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return 0;
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}
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