《C程序设计》期末复习练习题及参考答案(3)(3)

}

int BinSearch(long a[], int n, long x) { int low, high, mid; low = 0; high = n - 1; while (low <= high) {

mid = (high + low) / 2; if (x > a[mid]) { low = mid + 1; } else if (x < a[mid]) { high = mid - 1; } else { return (mid); } }

return(-1); }

2. 输入一行字符，统计其中的英文字符、数字字符、空格及其它字符的个数。 #include #include #define ARR_SIZE 80 main() {

char str[ARR_SIZE];

int len, i, letter=0, digit=0, space=0, others=0; gets(str); for (i=0; str[i]!='\\0'; i++) {

if (str[i] >= 'a' && str[i] <= 'z' || str[i] >= 'A' && str[i] <= 'Z') letter ++;

else if (str[i] >= '0' && str[i] <= '9') digit ++; else if (str[i] == ' ') space ++; else others ++; }

printf(\ %d\\n\ printf(\ %d\\n\ printf(\ %d\\n\

printf(\ %d\\n\

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}

3．以下程序为求出并打印1000以内所有水仙花数，请补齐代码。所谓水仙花数是指一个3位正整数，其各位数字的立方和等于该正整数。例如407 = 4* 4 * 4+0*0*0+7*7*7，故407是一个水仙花数. #include int main() { int x, y, z, a[100], m, i = 0, j = 0; printf(\ for( m=100; m<1000 ___________; m++) { x = m / 100; y = m/10 ; z = m ; if(x * 100 + y * 10 + z == x * x * x + y * y * y + z * z * z) { a[i] = m ; i++ ; } } for(j = 0; j < i; j++) printf(\ printf(\ return 0; }

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