输入的前六位数表示一个小数，然后输入一个数表示几次方。要求用高精度算出结果。
高精度水题，主要注意处理小数点，先在输入时把小数点提取出来并记录位置，用普通乘法计算出结果后由后向前计算位置添加小数点。
代码：
#include <cstdio>
#include <cstring>
const int maxn = 300;
void Mul(char *str1, char *str2, char *str3){
int i, j, i1, i2, tmp, carry, jj;
int len1 = strlen(str1), len2 = strlen(str2);
char ch;
jj = carry = 0;
for( i1=len1-1; i1 >= 0; --i1 ){
j = jj;
for( i2=len2-1; i2 >= 0; --i2, ++j ){
tmp =
(str3[j]-'0')+(str1[i1]-'0')*(str2[i2]-'0')+carry;
if( tmp > 9 ){
carry = tmp/10; str3[j] = tmp%10+'0';
}
else {
str3[j] = tmp+'0'; carry = 0;
}
}
if( carry ) {
str3[j] = carry+'0'; carry = 0; ++j;
}
++jj;
}
--j;
while( str3[j] == '0' && j > 0 ) --j;
str3[++j] = ' ';
for( i=0, --j; i < j; ++i, --j ){
ch = str3[i]; str3[i] = str3[j]; str3[j] = ch;
}
}
int main() {
char num[maxn], res[maxn], t[maxn];
int n;
while (1) {
int p, tmp, i = 0;
while ((tmp = getchar()) != EOF && tmp != ' ')
if (tmp == '.')
p = i;
else{
t[i]= num[i] = tmp;
i++;
}
for (int j = i - 1; j >= 0; j--)
if (num[j] != '0') {
i = j + 1;
break;
}
t[i] = num[i] = ' ';
if (scanf("%d", &n) == EOF)
break;
p = (strlen(num) - p) * n;
getchar();
memset(res, '0', sizeof(res));
for (int i = 0; i < n - 1; i++) {
Mul(num, t, res);
// if (i == n - 1)
// printf("%s %s %s
", num, t, res);
//printf("hehe
%s
", res);
if (i != n - 2)
for (int j = 0; j < maxn; j++) {
t[j] = res[j];
res[j] = '0';
}
}
if (p >= strlen(res)) {
printf(".");
for (int i = 0; i < p - strlen(res); i++)
printf("0");
printf("%s
", res);
}
else {
int i;
for (i = 0; i < strlen(res) - p; i++)
printf("%c", res[i]);
printf(".");
printf("%s
", res + strlen(res) - p);
}
}
return 0;
}