poj 1080

LCS的变形；

这一次才充分理解LCS；

dp[i+1][j+1]

dp[i][j+1]代表i被使用

同理代表j被使用

代码如下

#include<cstdio>#include<iostream>#include<cstring>#include<algorithm>using namespace std;int value[5][5]={{5,-1,-2,-1,-3},{-1,5,-3,-2,-4},      {-2,-3,5,-2,-2},      {-1,-2,-2,5,-1},      {-3,-4,-2,-1,0}};int getans(char a,char b){int num1,num2;if(a=='A') num1=0;if(a=='C') num1=1;if(a=='G') num1=2;if(a=='T') num1=3;if(a=='-') num1=4;if(b=='A') num2=0;if(b=='C') num2=1;if(b=='G') num2=2;if(b=='T') num2=3;if(b=='-') num2=4;return value[num1][num2];}int main(){int t;scanf("%d",&t);while(t--){int len1,len2;char a[105],b[105];scanf("%d%s",&len1,a);scanf("%d%s",&len2,b);int dp[105][105];memset(dp,0,sizeof(dp));for(int i=1;i<=len1;i++)dp[i][0]=dp[i-1][0]+getans(a[i-1],'-');for(int i=1;i<=len2;i++)dp[0][i]=dp[0][i-1]+getans('-',b[i-1]);for(int i=0;i<len1;i++)for(int j=0;j<len2;j++){dp[i+1][j+1]=dp[i][j]+getans(a[i],b[j]);dp[i+1][j+1]=max(dp[i+1][j+1],dp[i][j+1]+getans(a[i],'-'));dp[i+1][j+1]=max(dp[i+1][j+1],dp[i+1][j]+getans('-',b[j]));}printf("%d\n",dp[len1][len2]);} }