UVa 327 - Evaluating Simple C Expressions

按理说应该是一个二叉树的题，许久以前用数组做的 ~

代码如下：

#include<stdio.h>#include<string.h>char m[33][33];int main(){#ifdef wct    freopen("sample.txt","r",stdin);#endif    char m[150],a[150],b[30],flag[100];    int value,i,j,len,count,flagnum,num[30],numval[30];    while(gets(m)!=NULL)    {        value=flagnum=count=0;        memset(b,0,sizeof(b));        memset(a,0,sizeof(a));        memset(flag,0,sizeof(flag));        len=strlen(m);        for(i=0; i<len; i++)            if(m[i]!=' ')                a[count++]=m[i];        count=0;        len=strlen(a);        for(i=0; i<len; i++)        {            if(a[i]>='a'&&a[i]<='z')            {                b[count]=a[i];                num[count]=a[i]-'a'+1;                numval[count++]=a[i]-'a'+1;                if(a[i+1]=='+'&&a[i+2]=='+')                {                    num[count-1]++;                    i+=2;                }                else if(a[i-1]=='+'&&a[i-2]=='+')                {                    num[count-1]++;                    numval[count-1]++;                }                if(a[i+1]=='-'&&a[i+2]=='-')                {                    num[count-1]--;                    i+=2;                }                else if(a[i-1]=='-'&&a[i-2]=='-')                {                    num[count-1]--;                    numval[count-1]--;                }            }            if(a[i]=='+')            {                if((a[i+2]=='-'&&a[i+1]=='-'&&(a[i-1]>='a'&&a[i-1]<='z'))||(a[i-2]=='-'&&a[i-1]=='-'&&(a[i+1]>='a'&&a[i+1]<='z')))                    flag[flagnum++]='+';                else if((a[i+1]=='-'&&a[i-1]=='-')||(a[i+1]=='+'&&a[i-1]=='+'))                    flag[flagnum++]='+';                else if((a[i+2]=='-'&&a[i+1]=='-'&&a[i-1]=='+')||(a[i+2]=='+'&&a[i+1]=='+'&&a[i-1]=='-'))                    flag[flagnum++]='+';                else if((a[i-1]>='a'&&a[i-1]<='z')&&(a[i+1]>='a'&&a[i+1]<='z'))                    flag[flagnum++]='+';            }            if(a[i]=='-')            {                if((a[i+2]=='+'&&a[i+1]=='+'&&(a[i-1]>='a'&&a[i-1]<='z'))||(a[i-2]=='+'&&a[i-1]=='+'&&(a[i+1]>='a'&&a[i+1]<='z')))                    flag[flagnum++]='-';                else if((a[i+1]=='-'&&a[i-1]=='-')||(a[i+1]=='+'&&a[i-1]=='+'))                    flag[flagnum++]='-';                else if((a[i+2]=='-'&&a[i+1]=='-'&&a[i-1]=='+')||(a[i+2]=='+'&&a[i+1]=='+'&&a[i-1]=='-'))                    flag[flagnum++]='-';                else if((a[i-1]>='a'&&a[i-1]<='z')&&(a[i+1]>='a'&&a[i+1]<='z'))                    flag[flagnum++]='-';            }        }        value+=numval[0];        j=1;        for(i=0; i<flagnum; i++)            if(flag[i]=='+')                value+=numval[j++];            else if(flag[i]=='-')                value-=numval[j++];        printf("Expression: %s\n",m);        printf("    value = %d\n",value);        for(j=0; j<=25; j++)            for(i=0; i<count; i++)                if(b[i]=='a'+j)                    printf("    %c = %d\n",b[i],num[i]);    }    return 0;}