poj 3405 How many 0's?

来源：互联网发布：php class中使用use 编辑：程序博客网时间：2024/05/22 03:08

题目要求统计从m到n 的数字当中，0出现了几次。比如 99-101： 99 100 101 这里0 出现了3次

#include <cstdio>   #include <iostream>#include <string.h>   #include <cmath>#include <vector>#include <algorithm>   using namespace std;typedef long long ll;#define sfint(x) scanf("%d",&x)#define sfint2(x,y) scanf("%d%d",&x,&y)#define sfint3(x,y,z) scanf("%d%d%d",&x,&y,&z)#define sfstr(c) scanf("%s",c)#define sfdl(x) scanf("%lf",&x)#define sfch(c) scanf("%d",&c)#define pfint(x) printf("%d\n",x)#define fr(i,s,n) for(int i=s;i<n;++i)#define _fr(i,n,s) for(int i=n-1;i>=s;--i)#define cl(a) memset(a,0,sizeof(a))void  count_digit(ll x,ll times,ll ans[]){if (x<=0) return ;ll a = x/10,b = x%10;fr(i , 0 ,10) ans[i] += a*times;fr(i , 1, b+1) ans[i] += times;count_digit(a-1,times*10,ans);while(a) ans[a%10] += (b+1)*times,a/=10;}ll ansa[10],ansb[10];ll a,b;int main(){while(1){scanf("%lld%lld",&a,&b);cl(ansa);cl(ansb);if (a== -1 && b == -1) break;if (a>0) a--;else ansb[0]++;count_digit(a,1,ansa);count_digit(b,1,ansb);printf("%lld\n",ansb[0]-ansa[0]);}return 0;}