问题 H: Wanna go back home

题目描述
Snuke lives on an infinite two-dimensional plane. He is going on an N-day trip. At the beginning of Day 1, he is at home. His plan is described in a string S of length N. On Day i(1≤i≤N), he will travel a positive distance in the following direction:

North if the i-th letter of S is N
West if the i-th letter of S is W
South if the i-th letter of S is S
East if the i-th letter of S is E
He has not decided each day’s travel distance. Determine whether it is possible to set each day’s travel distance so that he will be back at home at the end of Day N.

Constraints
1≤|S|≤1000
S consists of the letters N, W, S, E.
输入
The input is given from Standard Input in the following format:
S
输出
Print Yes if it is possible to set each day’s travel distance so that he will be back at home at the end of Day N. Otherwise, print No.
样例输入 Copy
SENW
样例输出 Copy
Yes
提示
If Snuke travels a distance of 1 on each day, he will be back at home at the end of day 4.

cin>>a;z=a.size();for(i=0;i<z;i++){if(a[i]==\'N\')b.n++;else if(a[i]==\'S\')b.s++;else if(a[i]==\'W\')b.w++;else if(a[i]==\'E\')b.e++;}if(b.s>0&&b.n>0&&b.e>0&&b.w>0)f=1;else if((b.s>0&&b.n>0)&&(b.e+b.w==0))f=1;else if((b.s+b.n==0)&&b.e>0&&b.w>0)f=1;else f=0;if(f==1)printf (\"Yes\");else if(f==0)printf (\"No\");}

不难，只要W E S N都大于0+特殊情况就可以了