学步园

#include <iostream><br /> #include <string><br /> using namespace std;</p> <p>const int maxn = 31;<br /> string currents[maxn];<br /> double map[maxn][maxn];<br /> int n, m;</p> <p>int GetIndex(string &s){<br /> int i;<br /> for(i=0; i<n; i++) {<br /> if(s == currents[i])<br /> return i;<br /> }<br /> return -1;<br /> }</p> <p>bool Floyd(){<br /> int i, j, k;<br /> for(k=0; k<n; k++) {<br /> for(i=0; i<n; i++) {<br /> for(j=0; j<n; j++)<br /> if(map[i][j] < map[i][k]*map[k][j])<br /> map[i][j] = map[i][k]*map[k][j];<br /> }<br /> }<br /> for(i=0; i<n; i++) {<br /> if(map[i][i] > 1)<br /> return true;<br /> }<br /> return false;<br /> }</p> <p>int main() {<br /> int count = 0;<br /> while(cin>>n && n) {<br /> int i;<br /> string s1, s2;<br /> double r;</p> <p> for(i=0; i<n; i++) {<br /> cin>>currents[i];<br /> map[i][i] = 1;<br /> }</p> <p> cin>>m;<br /> for(i=0; i<m; i++) {<br /> cin>>s1;<br /> cin>>r;<br /> cin>>s2;<br /> map[GetIndex(s1)][GetIndex(s2)] = r;<br /> }</p> <p> printf("Case %d: ", ++count);<br /> if (Floyd())<br /> printf("Yes/n");<br /> else<br /> printf("No/n");<br /> }<br /> return 0;<br /> }<br />