http://acm.hdu.edu.cn/showproblem.php?pid=5062
模拟筛出对称单峰数(12321)的个数,水题
#include <cstdio> #include <cstdlib> #include <cmath> #include <cstring> #include <string> #include <queue> #include <set> #include <iostream> #include <algorithm> using namespace std; #define RD(x) scanf("%d",&x) #define RD2(x,y) scanf("%d",&x,&y) #define RD3(x,y,z) scanf("%d%d%d",&x,&y,&z) #define clr0(x) memset(x,0,sizeof(x)) typedef long long LL; int n; char s[10]; const double pi = acos ( -1.0 ) ; bool ok(int x) { int y = 0; while(x){ s[y++] = x%10; x /= 10; } for(int i = 0,j = y - 1;i <= j;++i,--j) if(s[i] != s[j] || (i >= 1 && s[i] <= s[i-1])) return false; return true; } void work() { int res = 0; n = (int)pow(10,n); //cout<<n; for(int i = 1;i <= n;++i){ if(ok(i)) res++; } printf("%d ",res); return; } int main () { int T; RD(T); while(T--){ RD(n); work(); } return 0 ; }