代码如下：

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

int i;
int tempa, tempb;
string s[51], temps;
char tempch = '+';
char *ch;

namespace prb {
	int digit(int num) {
		int ans = 0;
		while (num != 0)
			num /= 10, ans++;
		return ans;
		//整形位数判断函数
	}
}

string str(int func, int x, int y, int xl, int yl) {
	temps = "\0";
	int funx = 1, funnum = 0, digit;
	for (int funi = y; funi >= x; funi--, funx *= 10)
		tempa = tempa + (s[func][funi] - '0') * funx;
	for (int funi = yl, funx = 1; funi >= xl; funi--, funx *= 10)
		tempb = tempb + (s[func][funi] - '0') * funx;
	if (tempch == '+')
		funnum = tempa + tempb;
	else if (tempch == '-')
		funnum = tempa - tempb;
	else if (tempch == '*')
		funnum = tempa * tempb;
	tempa = 0, tempb = 0;
	if (funnum < 0)
		temps.push_back('-');
	funnum = abs(funnum);
	digit = prb::digit(funnum);
	while (funnum != 0) {
		temps.push_back((funnum % 10) + '0');
		funnum /= 10;
	}
	if (temps[0] == '-')
		reverse(temps.begin() + 1, temps.end());
	else
		reverse(temps.begin(), temps.end());
	return temps;
}

int main() {

	cin >> i;
	temps = getchar();
	for (int tempi = 0; tempi < i; tempi++) {

		getline(cin, s[tempi]);
		if (s[tempi][0] == 'a') {
			tempch = '+';
			s[tempi] = s[tempi].substr(2, s[tempi].size() - 2);
		} else if (s[tempi][0] == 'b') {
			tempch = '-';
			s[tempi] = s[tempi].substr(2, s[tempi].size() - 2);
		} else if (s[tempi][0] == 'c') {
			tempch = '*';
			s[tempi] = s[tempi].substr(2, s[tempi].size() - 2);
		}
		for (int tempj = s[tempi].size() - 1; tempj >= 0; tempj--) {
			if (s[tempi][tempj] == ' ') {
				s[tempi][tempj] = tempch;
				s[tempi] = s[tempi] + '=' + str(tempi, 0, tempj - 1, tempj + 1, s[tempi].size() - 1);
				break;
			}
		}
	}
	for (int tempi = 0; tempi < i; tempi++) {
		cout << s[tempi] << endl;
		cout << s[tempi].size() << endl;
	}
	return 0;
}

测试点1测试代码 只改动了输出 将75-78行代码改为

for (int tempi = 0; tempi < i; tempi++)
{
		cout << "99+999=1098" << endl;
		cout << 11 << endl;
}

能过 改为

for (int tempi = 0; tempi < i; tempi++)
{
	if (s[tempi] == "99+999=1098")
	{
		cout << "99+999=1098" << endl;
		cout << 11 << endl;
	}
}

不能过。 这是为什么。 dev运行一模一样。