https://www.luogu.com.cn/problem/P1045
#include<iostream> #include<cmath> using namespace std; int P; long long a[510]; long long POW2(int a){ long long res = 1; for (int i = 1; i <= a; i++){ res *= 2; } return res; } int main() { cin >> P; cout << ceil(P * log10(2)) << endl; // 第一问 long long tmp = POW2(32); // tmp=2^32 a[500] = 1; int t32 = P / 32; // t32：能乘以2^32的次数 int t1 = P - t32 * 32; // t1： 剩下的，一个一个乘上去 for (int T = 1; T <= t32; T++) { for (int i = 500; i >= 1; i--){ a[i] *= tmp; // 每一位都乘上2^32 } for (int i = 500; i >= 1; i--){ a[i - 1] += a[i] / 10; a[i] %= 10; // 处理进位 } } for (int T = 1; T <= t1; T++) { for (int i = 500; i >= 1; i--) { a[i] *= 2; // 每一位都乘上2 } for (int i = 500; i >= 1; i--){ a[i - 1] += a[i] / 10; a[i] %= 10; // 处理进位 } } a[500]--; for (int i = 1; i <= 500; i++) { cout << a[i]; if (i % 50 == 0) cout << endl; } return 0; }快速幂代码：
//求x^n int fastPower(int x, int n) { if (n == 0) return 1; int result = fastPower(x, n >> 1); result *= result; return (n & 1) == 0 ? result : result * x; }https://www.luogu.com.cn/problem/P1303
#include<iostream> #include<string> #include<cstdio> #include<algorithm> using namespace std; string a1, b1;//用string存入数据 int a[10001], b[10001], i, x, len, j, c[10001]; int main() { cin >> a1 >> b1; int lena = a1.size(); int lenb = b1.size(); //倒序存入数据 for (i = 1; i <= lena; i++)a[i] = a1[lena - i] - '0'; for (i = 1; i <= lenb; i++)b[i] = b1[lenb - i] - '0'; for (i = 1; i <= lenb; i++) for (j = 1; j <= lena; j++) c[i + j - 1] += a[j] * b[i]; for (i = 1; i < lena + lenb; i++) if (c[i] > 9) { c[i + 1] += c[i] / 10; c[i] %= 10; } len = lena + lenb; //去除高位的0 while (c[len] == 0 && len > 1)len--; for (i = len; i >= 1; i--)cout << c[i]; return 0; }错位相加代码：
for (i = 1; i <= lenb; i++) for (j = 1; j <= lena; j++) c[i + j - 1] += a[j] * b[i];https://www.luogu.com.cn/problem/P1249
#include<iostream> using namespace std; long long n, x = 0, s1 = 0, i = 2, t = 1; int a[10001]; int s[10001]; void cj(int x) { for (int i = 1; i <= t; i++) s[i] = s[i] * x; //t表示位数，x是乘数 //下面是进位处理 for (int i = 1; i <= t; i++) { if (s[i] >= 10) { long long x = s[i] / 10; s[i + 1] += x; s[i] %= 10; //位数等于当前位置+1，t=i+1与t++等效 if (i + 1 > t) t = i + 1; } } } int main() { s[1] = 1; cin >> n; //找出乘数序列 while (s1 < n) { a[++x] = i; s1 += i; i++; } //多出来的数字的序列的那位为0 a[s1 - n - 1] = 0; for (int i = 1; i <= x; i++) { //输出第一问 if (a[i] != 0) cout << a[i] << ' '; //累乘 if (a[i] != 0) cj(a[i]); } cout << endl; for (int i = t; i >= 1; i--) cout << s[i]; return 0; }