#include<iostream> #include<string> using namespace std; string str1, str2; int main() { int i = 0, j = 0, k = 0, num, n = 1, m; cout << "Enter a line of text: "; getline(cin, str1); str2.resize(str1.size() * 40); while (i < str1.size() && str1[i] != '\r ') { i++; while (i >= 40) { cout << "Input error, please re-enter:"; getline(cin, str1); i = 0; j = 0; } if (str1[i] == ' ') { j++;//Calculate the number of spaces } } cout << "1234567890123456789012345678901234567890" << endl; if (j == 0) { num = 40 - i; } else { num = (40 - i) / j; } if (((40 - i) % j)==0) { i = 0; while (i < str1.size() && str1[i] != '\r ' &&k < str2.size()) { str2[k++] = str1[i]; if (str1[i] == ' ') { for (int m = 1; m < num; m++) { str2[k++] = ' '; } } i++; } } else { i = 0; while (i < str1.size() && str1[i] != '\r ' && k < str2.size()) { str2[k++] = str1[i]; if (str1[i] == ' ') { if (n < j) { for (m = 1; m <= num+1; m++) { str2[k++] = ' '; } } else { for (m = 1; m <= num; m++) { str2[k++] = ' '; } } m++; } i++; } } cout << str2 << endl; }在这段代码基础上实现一下效果 Enter a line of text: Hello there! How are you today? 1234567890123456789012345678901234567890 Hello there! How are you today?

可以按照如下方式修改代码来实现该效果：

#include<iostream>
#include<string>
using namespace std;

string str1, str2;

int main() {
    int i = 0, j = 0, k = 0, num, n = 1, m;
    cout << "Enter a line of text: ";
    getline(cin, str1);
    str2.resize(str1.size() * 40);

    while (i < str1.size() && str1[i] != '\r ') {
        i++;
        while (i >= 40) {
            cout << "Input error, please re-enter:";
            getline(cin, str1);
            i = 0;
            j = 0;
        }
        if (str1[i] == ' ') {
            j++;//Calculate the number of spaces
        }
    }

    cout << "1234567890123456789012345678901234567890" << endl;

    if (j == 0) {
        num = 40 - i;
    }
    else {
        num = (40 - i) / j;
    }

    if (((40 - i) % j) == 0) {
        i = 0;
        while (i < str1.size() && str1[i] != '\r ' && k < str2.size()) {
            str2[k++] = str1[i];
            if (str1[i] == ' ') {
                for (int m = 1; m < num; m++) {
                    str2[k++] = ' ';
                }
            }
            i++;
        }
    }
    else {
        i = 0;
        while (i < str1.size() && str1[i] != '\r ' && k < str2.size()) {
            str2[k++] = str1[i];
            if (str1[i] == ' ') {
                if (n < j) {
                    for (m = 1; m <= num+1; m++) {
                        str2[k++] = ' ';
                    }
                }
                else {
                    for (m = 1; m <= num; m++) {
                        str2[k++] = ' ';
                    }
                }
                n++;
            }
            i++;
        }
    }

    cout << str2 << endl;
}

输入样例：Hello there! How are you today?

输出样例：

Enter a line of text: Hello there! How are you today?
1234567890123456789012345678901234567890
Hello   there!   How   are   you  today?