【状态压缩DP】HDU 2167

int g[16][16];
int st[1001];
char str[101];
int dp[16][(1<<15)];
int num[16][1001];
int n;
int tot;
bool ok(int x){
if(x & (x<<1))return 0;
if(x & (x>>1))return 0;
return 1;
}
void init(){
tot = 0;
int i;
for(i=0;i<(1<<n);i++){
if(ok(i)){
st[tot++] = i;
}
}
}
int cal(int x,int y){
int res = 0;
int i,j;
int m = st[y];
int cnt =0 ;
while(m){
if(m&1)res += g[x][cnt];
cnt++;
m>>=1;
}
return res;
}
void gao(){
memset(dp,0,sizeof(dp));
int i,j,k;
for(i=0;i<n;i++){
for(j=0;j<tot;j++){
if(!i){dp[i][j] = num[i][j];continue;}
for(k=0;k<tot;k++){
if(st[j] & st[k])continue;
if(st[j] & (st[k]<<1))continue;
if(st[j] & (st[k]>>1))continue;
dp[i][j] = max(dp[i][j], dp[i-1][k]+num[i][j]);
}
}
}
int ans = 0;
for(i=0;i<tot;i++){
ans = max(ans,dp[n-1][i]);
}
printf("%d\n",ans);
}

int main(){
int i = 0,j;
while(gets(str)){
n = 0;
int sum = 0;
for(i=0;str[i];i++){
if(str[i]==' '){
g[0][n++] = sum;
sum = 0;
} else {
sum = sum*10+str[i]-'0';
}
}
g[0][n++] = sum;

for(i=1;i<n;i++){
gets(str);
int m = 0;
sum =0 ;
for(j=0;str[j];j++){
if(str[j]==' '){
g[i][m++] = sum;
sum =0 ;
} else {
sum = sum*10+str[j]-'0';
}
}
g[i][m++] = sum;
}
init();
for(i=0;i<n;i++){
for(j=0;j<tot;j++){
num[i][j] = cal(i,j);
}
}
gao();
getchar();
}
return 0;
}