排序算法之计数排序

 

题目传送门

 1 /*  2  用UVA 11462 Age Sort来验证算法的正确性  3 */  4 #include <cstdio>  5 #include <cstring>  6 #include <algorithm>  7 #include <string>  8 #include <cmath>  9 #include <vector> 10 #include <map> 11 #include <set> 12 #include <cmath> 13 using namespace std; 14 15 const int MAX_N = 2000000 + 10; 16 int a[MAX_N], w[MAX_N], p[MAX_N], o[MAX_N]; 17 18 void BucketSort(int *a, int n, int mx) 19 { 20 memset (w, 0, sizeof (w)); 21 for (int i=1; i<=n; ++i) 22  { 23 w[a[i]]++; 24  } 25 for (int i=1; i<=mx; ++i) 26  { 27 w[i] += w[i-1]; 28  } 29 for (int i=1; i<=n; ++i) 30  { 31 p[i] = w[a[i]]; 32 w[a[i]]--; 33  } 34 for (int i=1; i<=n; ++i) 35  { 36 o[p[i]] = i; 37  } 38 } 39 40 int main(void) //UVA 11462 Age Sort 41 { 42 //freopen ("rand_small.in", "r", stdin); 43 int n; 44 45 while (scanf ("%d", &n) != EOF && n) 46  { 47 int mx = 0; 48 for (int i=1; i<=n; ++i) 49  { 50 scanf ("%d", &a[i]); 51 if (a[i] > mx) 52  { 53 mx = a[i]; 54  } 55  } 56  BucketSort (a, n, mx); 57 58 for (int i=1; i<=n; ++i) 59  { 60 printf ("%d%c", a[o[i]], (i==n) ? '\n' : ' '); 61  } 62  } 63 64 return 0; 65 }

 

 1 /*  2  用UVA 11462 Age Sort来验证算法的正确性  3  我不知道它究竟是啥算法，计数，基数or桶排序？不过比上一个好的感觉:)  4 */  5 #include <cstdio>  6 #include <algorithm>  7 #include <cstring>  8 using namespace std;  9 10 const int MAX_N = 2000000 + 10; 11 int a[MAX_N]; 12 int num[MAX_N]; 13 14 void BucketSort(int *a, int p, int r) 15 { 16 for (int i=p; i<=r; ++i) 17  { 18 num[a[i]]++; 19  } 20 } 21 22 int main(void) //UVA 11462 Age Sort 23 { 24 freopen ("rand_small.in", "r", stdin); 25 26 int n; 27 while (scanf ("%d", &n) != EOF && n) 28  { 29 memset (num, 0, sizeof (num)); 30 int mx = -1; 31 for (int i=1; i<=n; ++i) 32  { 33 scanf ("%d", &a[i]); 34 if (a[i] > mx) mx = a[i]; 35  } 36 37 BucketSort (a, 1, n); 38 39 for (int i=0; i<=mx; ++i) 40  { 41 if (num[i] == 0) continue; 42 else 43  { 44 for (int j=1; j<=num[i]; ++j) 45  { 46 printf ("%d%c", i, (i==mx && j==num[i]) ? '\n' : ' '); 47  } 48  } 49  } 50  } 51 52 return 0; 53 }