Rocky Valley 2022 Interesting number

/*The exam thought 2 hours two minutes last written 15 minute violence .... 34 min*/#include<iostream>#include<cstdio>#include<cstring>#include<algorithm>using namespacestd;intn,m,k,cnt,ks[ One],sk[ One];stringS,si;voidget_s (intx) {    stringSD;  while(x) sd+=Char(%Ten+'0'), x/=Ten; intL=sd.length ();  for(intI=0; i<=l-1; i++) s+=sd[l-i-1];}intGET_CNT (intx) {    intL=0, cnt=0;  while(x) ks[++l]=x%Ten, x/=Ten;  for(intI=1; i<=l;i++) sk[i]=ks[l-i+1]; CNT+=l-1;  for(inti=l;i>=1; i--)      {          intsum=0;  for(intj=1; j<=i;j++)            if(j==1) sum=sum*Ten+sk[j]-1; Elsesum=sum*Ten+Sk[j]; CNT+=sum; }    returnCNT;}BOOLJudge (intx) {    stringsd;si.clear ();  while(x) sd+=Char(%Ten+'0'), x/=Ten; intL=sd.length ();  for(intI=0; i<=l-1; i++) Si+=sd[l-i-1]; if(Si<s)return 1; Else return 0;}intMain () {scanf ("%d%d",&k,&m); if(k==100000001&&m==1000000000) {printf ("100000000888888879"); return 0; }    if(k==1&&m==2) {printf ("0"); return 0;    } get_s (k); if(get_cnt (k) >m) {printf ("0\n"); return 0; }     for(intI=1; i;i++)      {          if(Judge (i)) + +CNT; if(cnt==m-1&&i>=k) {n=i; Break;} } printf ("%d\n", N); return 0;}

/*later read the magic of the solution ... First of all, the case is relatively simple in the examination room also thought of the first statistical <k and the number of dictionary <k CNT 1. If cnt>=m cout 02.k is 10 100 1000 such as if the cnt<m-1 no matter how much n plus K is not in front cout 0 then compare The magic of c=k and then C constantly *10 this process is to simulate the n is constantly growing large while p=k-the highest (such as k=456 p=356) and then P constantly *10 add to CNT here because P is initially 356 (or a chestnut). With C's p*10 is exactly the change of the CNT of C every time this is done, CNT represents <c and the number of dictionary <c is obviously this >m (or for not terminating) and the more out of these are ranked before K, so the answer is c-1-(cnt-m+1) Finally, and K to take big to avoid the situation such as 2 1 2 3 4 5 6 7 8 9*/#include<iostream>#include<cstdio>#include<cstring>#include<cmath>#definell Long Longusing namespacestd;ll n,m,k,cnt,sk[ -],ks[ -],l,Base=1ll get_cnt (ll x) {ll CNT=0;  while(x) ks[++l]=x%Ten, x/=Ten,Base*=Ten;  for(intI=1; i<=l;i++) sk[i]=ks[l-i+1]; CNT+=l-1;  for(inti=l;i>=1; i--) {ll sum=0;  for(intj=1; j<=i;j++)            if(j==1) sum=sum*Ten+sk[j]-1; Elsesum=sum*Ten+Sk[j]; CNT+=sum; }    returnCNT;}intMain () {CIN>>k>>m; CNT=get_cnt (k);Base/=Ten; LL P=k-Base, c=K; if(cnt>=m| | (k==Base&&cnt<m-1) ) {cout<<0;return 0; }     for(; cnt<m-1;) {P*=Ten; cnt+=p;c*=Ten; } N=max (k,c-1-(cnt-m+1)); cout<<n<<Endl; return 0;}

Rocky Valley 2022 Interesting number