c++ primer 练习 1.9、1.10、1.11

1.9

#include<iostream>int main(){    int sum = 0, val = 50;    while(val <= 100) {        sum += val;        ++val;    }    std::cout << "Sum of 50 to 100 inclusive is " << sum << std::endl;    return 0;}

1.10

#include<iostream>int main(){    int val = 10;    while(val >= 0) {        std::cout << val << std::endl;        --val;    }    return 0;}

1.11

#include<iostream>int main(){    std::cout << "Enter two numbers: " << std::endl;    int v1 = 0, v2 = 0;    std::cin >> v1 >> v2;    while(v1 <= v2) {        std::cout << v1++ << std::endl;    }    return 0;}