#include <bits/stdc++.h> using namespace std; int main(){ int a[100][100] = {0}; int r[100] = {0}; int i,j,n; cin>>n; a[0][0] = 1; int k = 1; for(i = 1;i <= n;i++){ for(j = 0;j < k;j++){ a[i][j] = a[i - 1][j] * 2; } for(j = 0;j < k;j++){ if(a[i][j] >= 10){ a[i][j + 1] = a[i][j + 1] + a[i][j] / 10; a[i][j] = a[i][j] % 10; } } if(a[i][k] > 0){ k++; } } //求和 for(i = 1;i <= n;i++){ for(j = 0;j < k;j++){ r[j] = r[j] + a[i][j]; if(r[j] >= 10){ r[j + 1] += r[j] / 10; r[j] = r[j] % 10; } } if(r[k] > 0){ k++; } } int p = 0; for(i = k - 1;i >= 0;i--){ if(r[i] != 0){ p = i; break; } } for(i = p;i >= 0;i--){ cout<<r[i]; } } /************************************************************** Problem: 1281 User: admin Language: C++ Result: Accepted Time:8 ms Memory:2072 kb ****************************************************************/