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  1. #include<iostream>
  2. #include<stdio.h>
  3. #include<cstring>
  4.  
  5. using namespace std;
  6.  
  7. bool all9(int num[],int n)
  8. {
  9.     for(int i=0;i<n;i++)
  10.     {
  11.         if(num[i]!=9)
  12.             return false;
  13.     }
  14.     return true;
  15. }
  16.  
  17. void printnum(int num[],int n)
  18. {
  19.     for(int i=0;i<n;i++)
  20.         {
  21.             printf("%d",num[i]);
  22.         }
  23.     printf("\n");
  24.  
  25. }
  26.  
  27. void genNextP(int num[],int n)
  28. {
  29.     int mid = n/2;
  30.     int l=mid-1;
  31.     int r=(n%2)?mid+1:mid;
  32.     bool flag;
  33.     if(all9(num,n))
  34.     {
  35.         printf("1");
  36.         for(int i=1;i<n;i++)
  37.         {
  38.             printf("0");
  39.         }
  40.         printf("1\n");
  41.     }
  42.     else
  43.     {
  44.             while(l>=0&&num[l]==num[r])
  45.             {
  46.                 l--;
  47.                 r++;
  48.             }
  49.             if(l<0 || num[l]<num[r]) //case 1: given is palindrome
  50.             {
  51.                 flag = true;
  52.             }
  53.             while(l>=0)
  54.             {num[r]=num[l];l--;r++;}
  55.  
  56.             if(flag)
  57.             {
  58.                 int carry=1;
  59.                 l=mid-1;
  60.                 r=(n%2)?mid+1:mid;
  61.                 if((n%2))
  62.                 {
  63.                     num[mid]+=carry;
  64.                     carry=(num[mid])/10;
  65.                     num[mid]=(num[mid])%10;
  66.                 }
  67.                 while(l>=0){
  68.                     num[l]+=carry;
  69.                     carry=(num[l])/10;
  70.                     num[l]=(num[l])%10;
  71.                     num[r]=num[l];
  72.                     l--;r++;
  73.                 }
  74.  
  75.             }
  76.  
  77.             printnum(num,n);
  78.     }
  79. }
  80.  
  81.  
  82. int main()
  83. {
  84.     int num[1000007],t;
  85.     unsigned long int l;
  86.     char s[1000007];
  87.     scanf("%d",&t);
  88.     while(t--)
  89.     {
  90.         scanf("%s",s);
  91.         l=strlen(s);
  92.         for(unsigned long int i=0;i<l;i++)
  93.             num[i]=s[i]-48;
  94.         genNextP(num,l);
  95.     }
  96.     return 0;
  97. }
  98.  
Success #stdin #stdout 0s 7904KB
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https://ideone.com/KHxMDR
language:
C++ (gcc 8.3)
created:
9 years ago
visibility:
public

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