用c++1.编写无符号数的转换： unsigned int unsignedToValue(char binary[],int n); 要求在main中从屏幕读入n个二进制数即0或者是1，调用unsignedToValue函数返 回此二进制数代表的无符号数的真值。 2.编写有符号数的转换： int intToValue(char binary[],int n); 要求在main中从屏幕读入n个二进制数即0或者是1，调用intToValue函数返回此 二进制数代表的有符号数的真值。 3.编写单精度浮点数的转换 float floatToValue(char binary[]); 要求在main中从屏幕读入32个二进制数即0或者是1，调用intToValue函数返回此 二进制数代表的浮点数的真值，要求能够输出非规格化数：无穷大，0，非数。

1. 无符号数的转换

#include <iostream>
#include <cmath>

using namespace std;

unsigned int unsignedToValue(char binary[], int n) {
    unsigned int result = 0;
    for (int i = 0; i < n; i++) {
        result += pow(2, n - i - 1) * (binary[i] - '0');
    }
    return result;
}

int main() {
    int n;
    cin >> n;
    char binary[n];
    for (int i = 0; i < n; i++) {
        cin >> binary[i];
    }
    unsigned int result = unsignedToValue(binary, n);
    cout << result << endl;
    return 0;
}

2. 有符号数的转换

#include <iostream>
#include <cmath>

using namespace std;

int intToValue(char binary[], int n) {
    int result = 0;
    int sign = 1;
    if (binary[0] == '1') {
        sign = -1;
        for (int i = 0; i < n; i++) {
            binary[i] = (binary[i] == '0') ? '1' : '0';
        }
        binary[0] = '0';
    }
    for (int i = 0; i < n; i++) {
        result += pow(2, n - i - 1) * (binary[i] - '0');
    }
    return sign * result;
}

int main() {
    int n;
    cin >> n;
    char binary[n];
    for (int i = 0; i < n; i++) {
        cin >> binary[i];
    }
    int result = intToValue(binary, n);
    cout << result << endl;
    return 0;
}

3. 单精度浮点数的转换

#include <iostream>
#include <bitset>
#include <cmath>

using namespace std;

float floatToValue(char binary[]) {
    bitset<32> bits(binary);
    int sign = bits[31];
    int exponent = 0;
    for (int i = 30, j = 0; i >= 23; i--, j++) {
        exponent += bits[i] * pow(2, j);
    }
    int fraction = 0;
    for (int i = 22, j = -1; i >= 0; i--, j--) {
        fraction += bits[i] * pow(2, j);
    }
    float result = 0;
    if (exponent == 0 && fraction == 0) {
        result = (sign == 1) ? -0.0 : 0.0;
    } else if (exponent == 255 && fraction == 0) {
        result = (sign == 1) ? -INFINITY : INFINITY;
    } else if (exponent == 255 && fraction != 0) {
        result = NAN;
    } else {
        exponent -= 127;
        result = pow(-1, sign) * (1 + fraction / pow(2, 23)) * pow(2, exponent);
    }
    return result;
}

int main() {
    char binary[32];
    for (int i = 0; i < 32; i++) {
        cin >> binary[i];
    }
    float result = floatToValue(binary);
    cout << result << endl;
    return 0;
}