#include <stdio.h>
#include <iostream>
using std :: cin;
int a[1997], i, cnt, ans;;
int main()
{
    while(cin >> a[++ i])
    	ans += a[i], cnt ++;
    i = 1;
    while(i < cnt)
    	printf("%d+", a[i ++]);
    printf("%d=%d\n", a[i], ans);
    return 0;
}

这不是循环题吗

#include <iostream>
#include <stack>
#include <cmath>
#include <vector>
#include <string.h>
#include <queue>
#include <stdio.h>
#include <iomanip>
#include <cstdio>
#include <algorithm>
#define int long long
using namespace std;
const int N = 1e5 + 10;
const int INF = 0x3f3f3f3f;
signed main()
{
    int n[N], ans = 0, i = 1, cnt = 0;
    char a;
	while(cin >> n[i] >> a)
    {
        ans += n[i++];//算得数
        cnt++;//为循环做准备
    }
    for(int i = 1; i <= cnt; i++)
    {
        cout << n[i];//输出数据
        if(i != cnt)//等号判断
        {
            cout << "+";//加号
        }
        else
        {
            cout << "=";//等号
        }
    }
    cout << ans << endl;
	return 0;
}

#include <bits/stdc++.h>
using namespace std;

int main()
{
    int n[10005], ans = 0, i = 1, cnt = 0;
    char a;
	while(cin >> n[i] >> a)
    {
        ans += n[i++];
        cnt++;
    }
    for(int i = 1; i <= cnt; i++)
    {
        cout << n[i];
        if(i != cnt)
        {
            cout << "+";
        }
        else
        {
            cout << "=";
        }
    }
    cout << ans << endl;
	return 0;
}