UVa 10783 - Odd Sum

题目：求给定区间内的奇数之和。

分析：简单题。1+3+...+2k-1 = k^2。

#include <stdio.h>#include <stdlib.h>#include <string.h>int main(){int T,a,b; while ( scanf("%d",&T) != EOF ) for ( int t = 1 ; t <= T ; ++ t ) {scanf("%d%d",&a,&b);if ( a%2 == 0 ) a += 1;a = (a-1)>>1;if ( b%2 == 0 ) b -= 1;b = (b+1)>>1;printf("Case %d: %d\n",t,b*b-a*a);}return 0;}