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  1. #include <stdio.h>
  2. #include <vector>
  3.  
  4. using namespace std;
  5.  
  6.  
  7. class Solution {
  8. public:
  9.     int firstMissingPositive(vector<int>& nums) {
  10.  
  11.         for (int i = 0; i < nums.size(); i++) {
  12.             if (nums[i] <= 0) {
  13.                 nums[i] = -1;
  14.             }
  15.         }
  16.         nums.push_back(-1);
  17.  
  18.         printf("Before ");
  19.         printv(nums);
  20.         printf("\n");
  21.  
  22.         for (int i = 0; i < nums.size(); i++) {
  23.  
  24.  
  25.             int start = nums[i];
  26.             while (start > 0 && start < nums.size()){
  27.                 int newStart = nums[start];
  28.                 nums[start] = 0;
  29.                 if (newStart == start) {
  30.                     break;
  31.                 }
  32.                 start = newStart;
  33.             }
  34.  
  35.             printf("After i %d --- ", i);
  36.             printv(nums);
  37.         }
  38.  
  39.         printf("\nAfter");
  40.         printv(nums);
  41.  
  42.         for (int i = 1; i < nums.size(); i++) {
  43.             if (nums[i] == 0) {
  44.                 return i;
  45.             }
  46.         }
  47.  
  48.         return nums.size();
  49.     }
  50.  
  51.     void printv(vector<int>& nums) {
  52.         for (int i = 0; i < nums.size(); i++)
  53.             printf("%d, ", nums[i]);
  54.         printf("\n");
  55.     }
  56. };
  57.  
  58. int main() {
  59. 	vector<int> a = {3,4,-1,1};
  60. 	Solution *s = new Solution();
  61.  
  62. 	printf("val is %d", s->firstMissingPositive(a));
  63. }
Success #stdin #stdout 0s 15232KB
comments (?)
stdin
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Standard input is empty
stdout
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Before 3, 4, -1, 1, -1, 

After i 0 --- 3, 0, -1, 0, 0, 
After i 1 --- 3, 0, -1, 0, 0, 
After i 2 --- 3, 0, -1, 0, 0, 
After i 3 --- 3, 0, -1, 0, 0, 
After i 4 --- 3, 0, -1, 0, 0, 

After3, 0, -1, 0, 0, 
val is 1
https://ideone.com/e8LHBs
language:
C++14 (clang 8.0)
created:
5 years ago
visibility:
public

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