计算1-2+3-4+5-6+...+99-100。
（1一2）十（3一4）十…十（99一100）=一1x50=一50绛旓細1-2+3-4+5-6+...+99-100=-50銆傝В绛旇繃绋嬪涓嬶細1-2=-1锛3-4=-1锛5-6=-1鐩村埌99-100=-1锛屽洜涓烘湁100涓暟锛屾瘡2涓暟涓缁勶紝鏁呬竴鍏辨湁50缁勫樊涓-1 鐨勬暟锛屽嵆 1-2+3-4+5-6+...+99-100 =锛1-2锛+锛3-4锛+锛5-6锛+...+锛99-100锛=-1 x 50 =-50 ...
绛旓細=(1-2)+(3-4)+(5-6)...(+2017-2018)+(2019-2020)= -1 -1 -1 ... -1 锛堜竴鍏2020梅2 = 1010涓級= - 1010 鍔犲噺娉璁＄畻锛氫粠鍔犳硶浜ゆ崲寰嬪拰缁撳悎寰嬪彲浠ュ緱鍑犱釜鍔犳暟鐩稿姞锛屽彲浠ヤ换鎰忎氦鎹㈠姞鏁扮殑浣嶇疆锛涙垨鑰呭厛鎶婂嚑涓姞鏁扮浉鍔犲啀鍜屽叾浠栫殑鍔犳暟鐩稿姞锛屽畠浠殑鍜屼笉鍙樸備緥濡傦細34+72+66+28=(34+66...
绛旓細1銆佺洿鎺ュ姞鍑忔硶銆1-2=-1锛3-4=-1锛5-6=-1鐩村埌99-100=-1锛屽洜涓烘湁100涓暟锛屾瘡2涓暟涓缁勶紝鏁呬竴鍏辨湁50缁勫樊涓-1 鐨勬暟锛屽嵆 1-2+3-4+5-6+...+99-100 =锛1-2锛+锛3-4锛+锛5-6锛+...+锛99-100锛=-1 x 50 =-50 2銆佺瓑宸暟鍒楃畻娉曘傛妸鐩稿姞鐨勬暟鍏堝姞璧锋潵锛屽嵆1+3+5+7+....
绛旓細锛1-2锛+锛3-4锛+锛5-6锛+鈥︹+锛97-98锛+锛99-100锛=(-1)脳50 =-50
绛旓細鍏辨湁2020涓暟锛屼篃灏辨槸鏈 2020梅2=1010瀵 閫氳繃瑙傚療鎴戜滑鍙戠幇锛1-2=-1 3-4=-1 5-6=-1 鈥︹2019-2020=-1 鎵鏈夌浉閭荤殑涓ゆ暟閮芥槸-1 鎴戜滑鍒氬垰璁＄畻杩囦簡锛屽垰濂藉垎鎴愪竴瀵逛竴瀵圭殑锛屾湁1010瀵癸紝涔熷氨鎰忓懗鐫鏈1010涓 -1鐩稿姞锛屾墍浠ユ渶缁堢粨鏋滄槸-1010 ...
绛旓細include<stdio.h> void main(){ int n,sum;printf("input a number:\n");scanf("%d",&n);if(n%2==0)sum=n/2;else sum=(n/2+n);printf("the sum is:%d\n",sum);}
绛旓細鍏堟瘡涓や釜涓缁勭粨鍚堬紝涓嶉毦鍙戠幇姣忎竴缁勭粨鏋滈兘鐩稿悓锛屽啀涔樹互缁勬暟灏卞彲浠ヤ簡锛庤В绛旓細瑙ｏ細1-2+3-4+5-6+鈥+2007-2008 =锛1-2锛+锛3-4锛+锛5-6锛+鈥+锛2007-2008锛=-1脳 2008 2 =-1脳1004 =-1004锛庢晠搴斿～-1004锛
绛旓細int n = 10; for (int i = 1; i <= n; i++) { if (i%2 != 0) { amount += i; } else if (i%2 == 0) { amount -= i; } } System.out.println("amount = " + amount);}
绛旓細鏂规硶涓:瑙:1-2+3-4+5-6...-98+99 =(1+3+5+7+...+99)-(2+4+6+8+...+98)=50脳(1+99)梅2-49脳(98+2)梅2 =50脳100梅2-49脳100梅2 =50脳50鈥49脳50 =50脳(50-49)=50脳1 =50 灏嗘鏁板垪杞寲涓轰袱涓瓑宸暟鍒楃殑宸紝绗竴涓瓑宸暟鍒楅椤逛负1锛屽叕宸负2锛涚浜屼釜绛夊樊鏁板垪...
绛旓細VB:dim i,s as inegter s=0 ...for i =1 to 100 setp 2 s=-1+s next i ...C :int i,s;s=0;for(i=1,i<=100,i+2)s=-1+s;...
