sort函数比较cmp写法

hihocoder1566http://hihocoder.com/problemset/problem/1566

一直WA因为cmp的写法写错了，未能正确实现排序功能。

 #include<iostream>

 #include<cstdio>

 #include<cstring>

 #include<algorithm>

 #include<cstdlib>

 #include<string>

 #include<cmath>

 #include<vector>

 #include<stack>

 #include<iterator>

 #include<queue>

 #include<cctype>

 #include<map>

 #define lson l, m, rt<<1

 #define rson m+1, r, rt<<1|1

 #define IO ios::sync_with_stdio(false);cin.tie(0);

 #define INF 0x3f3f3f3f

 #define MAXN 100010

 const int MOD=1e9+;

 typedef long long ll;

 using namespace std;

 int t;

 typedef struct {

     char s1[], s2[];

     int sum;

 }Node;

 Node node[];

 map<char, int> mp;

 int cal(const char s[])

 {

     int len = strlen(s), ans=, last=mp[s[len-]];

     for(int i = len-; i >= ; i--){

         if(last-mp[s[i]] > ){

             last -= mp[s[i]];

         }

         else{

             ans += last;

             last = mp[s[i]];

         }

     }

     ans += last;

     return ans;

 }

 bool cmp(const Node a, const Node b)

 {

     if(strcmp(a.s1, b.s1) != ) return strcmp(a.s1, b.s1)<;

     else{

         return a.sum < b.sum;

     }

 }

 int main()

 {

     IO;

     mp['I']=;mp['V']=;mp['X']=;mp['L']=;mp['C']=;mp['D']=;mp['M']=;

     cin >> t;

     for(int i = ; i < t; i++){

         cin >> node[i].s1 >> node[i].s2;

         node[i].sum = cal(node[i].s2);

         //cout << cal(node[i].s2) << endl;

     }

     sort(node, node+t, cmp);

     for(int i = ; i < t; i++){

         cout << node[i].s1 << " " << node[i].s2 << endl;

     }

     return ;

 }