怎么看都没看出错误啊，

#include <iostream>

using namespace std;

int main() {
    int a, b, c;
    cin >> a >> b >> c;
    
    // 如果三条线段不能组成一个三角形
    if (not(a + b > c or a + c > b or b + c > a)) {
        cout << "Not triangle";
    }
    
    // 如果是直角三角形
    if (a < c and b < c and a * a + b * b == c * c or a < b and c < b and a * a + c * c == b * b or b < a and c < a and b * b + c * c == a * a) {
        cout << "Right triangle";
    }
    
    // 如果是锐角三角形
    if (a < c and b < c and a * a + b * b > c * c or a < b and c < b and a * a + c * c > b * b or b < a and c < a and b * b + c * c > a * a) {
        cout << "Acute triangle";
    }
    
    // 如果是钝角三角形
    if (a < c and b < c and a * a + b * b < c * c or a < b and c < b and a * a + c * c < b * b or b < a and c < a and b * b + c * c < a * a) {
        cout << "Obtuse triangle";
    }
    
    // 如果是等腰三角形
    if (a == b or a == c or b == c) {
        cout << "Isosceles triangle";
    }
    
    // 如果是等边三角形
    if (a == b and b == c) {
        cout << "Equilateral triangle";
    }
    
    cout << endl;
    return 0;
}

求巨佬解答！