Codeforces Round #197 (Div. 2)

A.Helpful Maths

分析：将读入的字符转化为数字，直接排个序就可以了。

#include <cstdlib>
#include <cstring>
#include <cstdio>
#include <algorithm>
using namespace std;

const int N = 500;
int seq[N];

int main() {
    char c;
    int t = 0, idx = 0;
    while ((c = getchar()) != EOF) {
        if (c == '+' || c == '\n') {
            seq[idx++] = t;
            t = 0;
        }
        else t = t * 10 + c - '0';
    }
    sort(seq, seq+idx);
    printf("%d", seq[0]);
    for (int i = 1;  i < idx; ++i) printf("+%d", seq[i]);
    puts("");
    return 0;
} 

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