【題解】ZeroJudge c022: 10783 – Odd Sum

#include<iostream>
using namespace std;

int main(){
    int T;
    cin >> T;
    for (int i = 1; i <= T; i++) {
        int a, b;
        cin >> a >> b;
        if (a % 2 == 0) {
            a += 1;
        }
        if (b % 2 == 0) {
            b -= 1;
        }
        int num=(b-a)/2+1;
        int total;
        total=(a+b)/2*num;
        cout << "Case " << i << ": ";
        cout << (a + b) / 2 * ((b - a) / 2 + 1) << "\n";
    }
}

#include <iostream>
using namespace std;

int main() {
    int T, a, b;
    cin >> T;
    for (int Case = 1; Case <= T; Case++) {
        cin >> a >> b;
        int sum = 0;
        if (a % 2 == 0) {
            a += 1;
        }
        for (int i = a; i <= b; i += 2) {
            sum += i;
        }
        cout << "Case " << Case << ": " << sum << "\n";
    }
    return 0;
}

T = int(input())
for TC in range(1, T+1):
    a = int(input())
    b = int(input())
    
    if a % 2 == 1:
        start = a
    else:
        start = a+1
    
    ans = 0
    for i in range(start, b+1, 2):
        ans += i
    print(f"Case {TC}: {ans}")