Problem link
Hints
Floyd-Warshall algorithm
Solution code
#include<cstdio>
#include<cstring>
using namespace std;
void floyd(int n);
void print(int x, int y, int p);
#define N 20
int seq[N][N][N];
double table[N][N][N];
int main(void){
int n;
while(scanf("%d",&n) != EOF){
memset(seq,0,sizeof(seq));
memset(table,0,sizeof(table));
for(int i=0;i<n;++i)
for(int j=0;j<n;++j)
if( i != j){
scanf("%lf",&table[i][j][0]);
seq[i][j][0]=i;
}
floyd(n);
}
return 0;
}
void floyd(int n){
for(int p=1;p<n;++p){
for(int i=0;i<n;++i)
for(int k=0;k<n;++k)
for(int j=0;j<n;++j)
if(table[i][k][p-1]*table[k][j][0] > table[i][j][p]){
table[i][j][p] = table[i][k][p-1]*table[k][j][0];
seq[i][j][p]=k;
}
for(int i=0;i<n;++i){
if(table[i][i][p] > 1.01){
print(i,i,p);
printf("\n");
return;
}
}
}
printf("no arbitrage sequence exists\n");
}
void print(int x, int y, int p){
if(p == -1){
printf("%d",x+1);
}else{
print(x,seq[x][y][p],p-1);
printf(" %d",y+1);
}
}