求 a^b（数学）

 数据量很大时  long long中间也会溢出  所以要拆分开来做

 # include <stdio.h>
 # include <string.h>
 # define LL long long
 
 LL i, len, n, m;
 LL a[110];
 
 void f(int n)
 {
     for(i = 0; i < len; i++)
         a[i] *= n;
     for(i = 0; i < len+100; i++)
     {
         a[i+1] += a[i]/10;
         a[i] %= 10;
     }
     for(i = len+100; i >= 0; i--)
     {
         if(a[i] != 0)
             break;
     }
     len = i+1;
 }
 
 int main(void)
 {
     int p;
     scanf("%d", &p);
     while(p--)
     {
         scanf("%lld%lld", &n, &m);
         if(m == 1)
             printf("
", n);
         else if(n == 0)
             printf("0
");
         else if(n == 1)
             printf("1
");
         else if(n < 0)
         {
             if(m % 2 == 1)
                 printf("-");
             n = -n;
         }
         memset(a, 0, sizeof(a));
         a[0] = 1;
         len = 1;
         for(int i = 1; i <= m; i++)
             f(n);
         for(i = len-1; i >= 0; i--)
             printf("%lld", a[i]);
         printf("
");
     }
 
     return 0;
 }