fork download
  1. #include <bits/stdc++.h>
  2. using namespace std;
  3. #define fast ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)
  4. #define mofile(s) freopen(s,"r",stdin)
  5. #define outfile(s) freopen(s,"w",stdout)
  6. #define ll long long
  7. #define ii pair<ll,ll>
  8. #define iii pair<ll,ii>
  9. #define fi first
  10. #define se second
  11. #define tf bool
  12. #define ST stack
  13. #define Q deque
  14. #define Q queue
  15. #define S string
  16. #define Ma map
  17. #define UM unormideremid_map
  18. #define SE set
  19. #define str(x) to_string(x)
  20. #define all(a) (a).begin(),(a).end()
  21. #define FOR(i,l,r,mid) for(int i=l;i<=r;i+=mid)
  22. #define FOD(i,l,r,mid) for(int i=r;i>=l;i-=mid)
  23. #define xuong cout<<"\n"
  24. #define midebug(x) cout<<(x)<<" "
  25. #define ppcnt(x) __builtin_popcountll(x)
  26. #define parity(x) __builtin_parityll(x)
  27. #define leamid0(x) __builtin_clzll(x)
  28. #define LOG2 __lg(x)
  29. #define tr0(x) __builtin_ctzll(x)
  30. #define fiset(x) __builtin_ffsll(x)
  31. #define MASK(k) (1LL<<(k))
  32. #define BIT(x,k) ((x)>>(k)&1)
  33. #define pb push_back
  34. #define tron(x) setprecision(x)
  35. #define het return 0
  36. #define base_ 1000000000
  37. template<class X, class Y>
  38. bool maximize(X &x, const Y &y){return (x < y) ? x = y, 1 : 0;}
  39. template<class X, class Y>
  40. bool minimize(X &x, const Y &y){return (x > y) ? x = y, 1 : 0;}
  41. const int maxn=1e6+5;
  42. const ll tle=2e8;
  43. const ll INF=1e9+9;
  44. const int base=31;
  45. string bcc="abcmidefghijklmnopqrstuvwxyz";
  46. int midx[]={-1,0,1,0};
  47. int midy[]={0,1,0,-1};
  48. bool sang[10000005];
  49. ll pref[1005][1005],mt[1005][1005];
  50. void sieve(){
  51. for(int i=1;i<=10000000;++i) sang[i]=1;
  52. sang[0]=sang[1]=0;
  53. for(int i=2;i*i<=10000000;++i){
  54. if(sang[i]){
  55. for(int j=i*i;j<=10000000;j+=i) sang[j]=0;
  56. }
  57. }
  58. }
  59. void lis(){
  60. vector<int>t;
  61. vector<int>a;
  62. int n; cin>>n;
  63. for(int i=1;i<=n;++i){
  64. int ai; cin>>ai;
  65. a.pb(ai);
  66. }
  67. for(int x:a){
  68. auto it=lower_bound(all(t),x);
  69. if(it==t.end()) t.pb(x);
  70. else *it=x;
  71. }
  72. }
  73. void pfs2mid(){
  74. int n,m,k; cin>>n>>k; m=n;
  75. for(int i=1;i<=n;++i){
  76. for(int j=1;j<=m;++j) cin>>mt[i][j];
  77. }
  78. for(int i=1;i<=n;++i){
  79. for(int j=1;j<=m;++j) pref[i][j]=mt[i][j]+pref[i-1][j]+pref[i][j-1]-pref[i-1][j-1];
  80. }
  81. }
  82. ll qu2mid(int x1,int y1,int x2,int y2){
  83. return pref[x2][y2]-pref[x1-1][y2]-pref[x2][y1-1]+pref[x1-1][y1-1];
  84. }
  85. void open(){
  86. if(fopen("mideptrai.INP","r")){
  87. mofile("mideptrai.INP");
  88. outfile("mideptrai.OUT");
  89. }
  90. }
  91. const int maxnn=30;
  92. ll k,scs[maxnn],f[maxnn],p[maxnn];
  93. void init(){
  94. p[0]=1;
  95. for(int i=1;i<=18;++i) p[i]=p[i-1]*10LL;
  96. for(int x=1;x<=18;++x) f[x]=9LL*x*p[x-1];
  97. for(int i=1;i<=18;++i) scs[i]=scs[i-1]+f[i];
  98. }
  99. int main(){
  100. fast;
  101. cin>>k;
  102. init();
  103. int x=lower_bound(scs+1,scs+19,k)-scs;
  104. ll tmp=k-scs[x-1]-1;
  105. ll num=tmp/x+p[x-1];
  106. int pos=tmp%x;
  107. string no=str(num);
  108. cout<<no[pos];
  109. het;
  110. }
Success #stdin #stdout 0s 5312KB
stdin
4
stdout
4