这题初看起来被吓到了,以为要写成运算符重载,后来发现其实很水,呵呵(但是某人虽然在poj过了,但是却在tojWA了5次,实在不解,呵呵) 思路:接入字符串,去掉空格,从头到尾扫,遇到字母就检测它的前后两位有没有++(--)如果有进行处理,然后看它的后(前)面第3为是+(-)就加(减)到和sum里;用一个三维数组v[26][3]记录状态和值。代码写的比较繁琐,呵呵,不想改了,易懂,嘿嘿。
1 #include<iostream> 2 using namespace std; 3 char a[500]; 4 char b[500]; 5 int v[26][3]; 6 int l; 7 bool inside(int a, int b) 8  { 9 if(a>=0 && a<l && b>=0 && b<l) 10 return true; 11 else 12 return false; 13 } 14 bool jia(int c, int b) 15  { 16 if(a[c]=='+' && a[b]=='+') 17 return true; 18 else 19 return false; 20 } 21 bool jian(int c, int b) 22  { 23 if(a[c]=='-' && a[b]=='-') 24 return true; 25 else 26 return false; 27 } 28 int main() 29  { 30 int n,i,j,k3,k4,k1,k2; 31 char c; 32 scanf("%d",&n); 33 scanf("\n"); 34 while(n--) { 35 36 int sum=0; 37 for(i=0; i<26; i++) 38 v[i][0]=i+1,v[i][1]=i+1,v[i][2]=0; 39 40 memset(a, 0, sizeof(a)); 41 memset(b, 0, sizeof(b)); 42 i=0;j=0; 43 while(scanf("%c",&c) && c!='\n') { 44 b[j]=c; 45 j++; 46 if(c!=' ') 47 a[i]=c,i++; 48 } 49 50 51 52 l=i;int count=0; 53 for(i=0; i<l; i++) 54 if(a[i]<='z' && a[i]>='a') { 55 count++; 56 v[a[i]-'a'][2]=1; 57 k1=i+1; 58 k2=i+2; 59 k3=i-1; 60 k4=i-2; 61 if(count==1) { 62 if(inside(k1,k2) && jia(k1,k2)) 63 v[a[i]-'a'][0]++; 64 else if(inside(k3,k4) && jia(k3,k4)) 65 v[a[i]-'a'][0]++,v[a[i]-'a'][1]++; 66 else if(inside(k1,k2) && jian(k1,k2)) 67 v[a[i]-'a'][0]--; 68 else if(inside(k3,k4) && jian(k3,k4)) 69 v[a[i]-'a'][0]--,v[a[i]-'a'][1]--; 70 71 sum+=v[a[i]-'a'][1];} 72 else { 73 if(inside(k1,k2) && jia(k1,k2)) { 74 v[a[i]-'a'][0]++; 75 if(a[i-1]=='+') 76 sum+=v[a[i]-'a'][1]; 77 else 78 sum-=v[a[i]-'a'][1]; 79 } 80 else if(inside(k3,k4) && jia(k3,k4)) { 81 v[a[i]-'a'][0]++,v[a[i]-'a'][1]++; 82 if(a[i-3]=='+') 83 sum+=v[a[i]-'a'][1]; 84 else 85 sum-=v[a[i]-'a'][1]; 86 } 87 else if(inside(k1,k2) && jian(k1,k2)) { 88 v[a[i]-'a'][0]--; 89 if(a[i-1]=='+') 90 sum+=v[a[i]-'a'][1]; 91 else 92 sum-=v[a[i]-'a'][1]; 93 } 94 else if(inside(k3,k4) && jian(k3,k4)) { 95 v[a[i]-'a'][0]--,v[a[i]-'a'][1]--; 96 if(a[i-3]=='+') 97 sum+=v[a[i]-'a'][1]; 98 else 99 sum-=v[a[i]-'a'][1]; 100 } 101 else 102 { 103 if(a[i-1]=='+') 104 sum+=v[a[i]-'a'][1]; 105 else 106 sum-=v[a[i]-'a'][1]; 107 } 108 } 109 } 110 printf("Expression: %s\n",b);; 111 printf("value = %d\n",sum); 112 for(i=0; i<26; i++) 113 if(v[i][2]==1) 114 printf("%c = %d\n",'a'+i,v[i][0]); 115 116 } 117 118 return 0; 119 }
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