Codeforces 339A Helpful Maths (greedy implementation sortings strings water problem)

A. Helpful Maths
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Time limit per test 2 seconds memory limit per test megabytes input standard input output standard output

Xenia The beginner mathematician is a third year student at elementary school. She's now learning the addition operation.

The teacher have written down the sum of multiple numbers. Pupils should calculate the sum. To make the calculation easier, the sum is only contains numbers 1, 2 and 3. Still, that's isn ' t enough for Xenia. She is only beginning to count, so she can calculate a sum only if the summands follow in non-decreasing order. For example, she can ' t calculate sum 1+3+2+1 But she can calculate sums 1+1+2 and 3+3.

You ' ve got the sum of that is written on the board. Rearrange the Summans and print the sum in such a to that Xenia can calculate the sum. Input

The first line contains a non-empty string s-the sum Xenia needs to count. String s contains no spaces. It is only contains digits and characters "+". Besides, string s is a correct sum of numbers 1, 2 and 3. String S is at the most characters long. Output

Print the new sum that Xenia can count. Sample Test (s) Input

3+2+1

Output

1+2+3

Input

1+1+3+1+3

Output

1+1+1+3+3

Input

2

Output

2 The
problem is the order from small to large output on the line, the ' + ' number unchanged.
Code:

#include <iostream> #include <string.h> #include <stdlib.h> using namespace std;
    int cmp (const void *a,const void *b) {return * (int *) a-* (int *) b;} int main () {char s[101];
    int a[101],i,j,k;
        while (cin>>s) {K=strlen (s);
            for (i=0,j=0;i<k;i++) {if (i%2==0) {a[j++]=s[i]-' 0 ';
        }} qsort (A,j,sizeof (a[0]), CMP);
            for (i=0,j=0;i<k;i++) {if (i%2==0) {s[i]=a[j++]+ ' 0 ';
        }} cout<<s<<endl;
    memset (S, ' n ', sizeof (s));
} return 0;

Another code that comes with another introduction on the Web: <pre name= "code" class= "CPP" > #include <iostream> using namespace std;
	int main () {string S;
	int I, J;
	char x;
	cin>>s;
	For (I=s.size ()-1; i>0; i-=2) for (j=0; j<i; j+=2) if (s[j]>s[j+2]) {x = S[j]; S[j] = s[j+2]; s[j+2] = x;
	} cout<<s;
return 0; }