FNOI_TEST_1 a（模拟）

连模拟都写不对了。。。太弱了。。。

#include <cstdio>#include <cstring>#include <cmath>#define ll long longll l,r;ll solve(ll x){//f[1]+...+f[x]    ll res=0;int n=log10(x)+1,a[11];    for(ll i=1,base=1;i<=n;++i,base*=10){//枚举第i位         a[i]=x%(base*10)/base;        for(ll j=1;j<=9;++j){//枚举第i位的数字j的贡献             ll tmp=x/(base*10)*base;            if(j==a[i]) tmp+=x%base+1;            if(j<a[i]) tmp+=base;            res+=j*tmp;        }    }    return res;}int main(){    freopen("a.in","r",stdin);    freopen("a.out","w",stdout);    scanf("%I64d%I64d",&l,&r);    printf("%I64d\n",solve(r)-solve(l-1));    return 0;}