Age Sort
You are given the ages (in years) of all people of a country with at least 1 year of age. You know that no individual in that country lives for 100 or more years. Now, you are given a very simple task of sorting all the ages in ascending order.
Input
There are multiple test cases in the input file. Each case starts with an integer n (0<n<=2000000), the total number of people. In the next line, there are n integers indicating the ages. Input is terminated with a case where n = 0. This case should not be processed.
Output
For each case, print a line with n space separated integers. These integers are the ages of that country sorted in ascending order.
Warning: Input Data is pretty big (~ 25 MB) so use faster IO.
Sample Input
5
3 4 2 1 5
5
2 3 2 3 1
0
Output for Sample Input
1 2 3 4 5
1 2 2 3 3
題目大意:給定若干居民的年齡(都是1-100之間的整數),把他們按照從小到大的順序輸出。
分析:年齡排序。由於資料太大,記憶體限制太緊(甚至都不能把他們全部讀進記憶體),因此無法使用快速排序方法。但整數範圍很小,可以用計數排序法。
程式碼如下:
1 #include<cstdio> 2 #include<cstring> 3 #include<cctype> // 為了使用isdigit巨集 4 5 inline int readint() { 6 char c = getchar(); 7 while(!isdigit(c)) c = getchar(); 8 9 int x = 0; 10 while(isdigit(c)) { 11 x = x * 10 + c - '0'; 12 c = getchar(); 13 } 14 return x; 15 } 16 17 int buf[10]; // 宣告成全域性變數可以減小開銷 18 inline void writeint(int i) { 19 int p = 0; 20 if(i == 0) p++; // 特殊情況:i等於0的時候需要輸出0,而不是什麼也不輸出 21 else while(i) { 22 buf[p++] = i % 10; 23 i /= 10; 24 } 25 for(int j = p-1; j >=0; j--) putchar('0' + buf[j]); // 逆序輸出 26 } 27 28 int main() { 29 int n, x, c[101]; 30 while(n = readint()) { 31 memset(c, 0, sizeof(c)); 32 for(int i = 0; i < n; i++) c[readint()]++; 33 int first = 1; 34 for(int i = 1; i <= 100; i++) 35 for(int j = 0; j < c[i]; j++) { 36 if(!first) putchar(' '); 37 first = 0; 38 writeint(i); 39 } 40 putchar('\n'); 41 } 42 return 0; 43 }