事情的开始是我在调试一段算法题的代码, 这段代码的算法比较复杂, debug 非常不便, 我便萌生出跟踪算法每一步的执行的想法, 尽管 IDE 提供了断点的功能, 但实在也不是特别方便, 于是我开发了 Prouter 算法示踪库

GitHub: https://github.com/Dynesshely/Prouter

下面是从仓库复制过来的 README:

About

Prouter is a library that allows you to trace your code and visualize your algorithm.

Usages

Includes

#include <prouter/includes.h> 

and you'd better include predefine.h after main function like this:

#include <prouter/includes.h> int main() { #include <prouter/predefine.h> ...... 

Trace a var

double a = 3.0; a = 4.0, a *= 2.0; std::cout << a.history() << std::endl << std::endl; 

Output:

3.000000 -> 4.000000 -> 8.000000 

Trace an array

auto int_arrTracer = prouter::traceArray().named("int arr tracer"); int intarr[10] = {0}; int_arrTracer.trace(intarr, 10); for (int i = 0; i < 10; ++i) intarr[i] = i; int_arrTracer.printTo(std::cout, true).dispose(); auto num_arrTracer = prouter::traceArray().named("num arr tracer"); double numarr[10] = {0}; num_arrTracer.trace(numarr, 10); for (int i = 0; i < 10; ++i) numarr[i] = i; std::cout << num_arrTracer.history() << std::endl; num_arrTracer.dispose(numarr); 

Output:

 int arr tracer [0, 0, 0, 0, 0, 0, 0, 0, 0, 0] [0, 1, 0, 0, 0, 0, 0, 0, 0, 0] [0, 1, 2, 0, 0, 0, 0, 0, 0, 0] [0, 1, 2, 3, 0, 0, 0, 0, 0, 0] [0, 1, 2, 3, 4, 0, 0, 0, 0, 0] [0, 1, 2, 3, 4, 5, 0, 0, 0, 0] [0, 1, 2, 3, 4, 5, 6, 0, 0, 0] [0, 1, 2, 3, 4, 5, 6, 7, 0, 0] [0, 1, 2, 3, 4, 5, 6, 7, 8, 0] [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] [0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000] [0.000000, 1.000000, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000] [0.000000, 1.000000, 2.000000, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000] [0.000000, 1.000000, 2.000000, 3.000000, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000] [0.000000, 1.000000, 2.000000, 3.000000, 4.000000, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000] [0.000000, 1.000000, 2.000000, 3.000000, 4.000000, 5.000000, 0.000000, 0.000000, 0.000000, 0.000000] [0.000000, 1.000000, 2.000000, 3.000000, 4.000000, 5.000000, 6.000000, 0.000000, 0.000000, 0.000000] [0.000000, 1.000000, 2.000000, 3.000000, 4.000000, 5.000000, 6.000000, 7.000000, 0.000000, 0.000000] [0.000000, 1.000000, 2.000000, 3.000000, 4.000000, 5.000000, 6.000000, 7.000000, 8.000000, 0.000000] [0.000000, 1.000000, 2.000000, 3.000000, 4.000000, 5.000000, 6.000000, 7.000000, 8.000000, 9.000000] 

Trace a loop

auto loopTracer = prouter::traceLoop().named("loop 1"); int f[13], i = 1, fc; f[1] = 1, f[2] = 1; loopTracer.trace(&i.named("i")) .trace(&fc.named("fc")) .trace(f, 13, 2); for (; i <= 10; ++i, loopTracer.loop()) { if (i >= 3) f[i] = f[i - 1] + f[i - 2]; fc.setValue(f[i]); } loopTracer.end().printTo(std::cout); 

Output:

 i fc default array tracer 0 1 -> 2 0 -> 1 [0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0] 1 2 -> 3 1 -> 1 [0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0] 2 3 -> 4 1 -> 2 [0, 1, 1, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0] 3 4 -> 5 2 -> 3 [0, 1, 1, 2, 3, 0, 0, 0, 0, 0, 0, 0, 0] 4 5 -> 6 3 -> 5 [0, 1, 1, 2, 3, 5, 0, 0, 0, 0, 0, 0, 0] 5 6 -> 7 5 -> 8 [0, 1, 1, 2, 3, 5, 8, 0, 0, 0, 0, 0, 0] 6 7 -> 8 8 -> 13 [0, 1, 1, 2, 3, 5, 8, 13, 0, 0, 0, 0, 0] 7 8 -> 9 13 -> 21 [0, 1, 1, 2, 3, 5, 8, 13, 21, 0, 0, 0, 0] 8 9 -> 10 21 -> 34 [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 0, 0, 0] 9 10 -> 11 34 -> 55 [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 0, 0] 

Trace a stack

auto pstackTest = (new stack<s_int>())->push(4) .push(8) .push(2) .pop() .push(9) .pop() .push(3) .pop() .push(1) .pop() .clear() .printHistoryTo(std::cout); 

Here use s_int to avoid using pint

Output:

 +---+ +---+ +---+ +---+ | | | | | | | | +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ --> | | --> | 2 | --> | | --> | 9 | --> | | --> | 3 | --> | | --> | 1 | --> | | --> +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ | | | 8 | | 8 | | 8 | | 8 | | 8 | | 8 | | 8 | | 8 | | 8 | +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ | 4 | | 4 | | 4 | | 4 | | 4 | | 4 | | 4 | | 4 | | 4 | | 4 | | | +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ 

Trace a queue

auto pqueueTest = (new queue<int>())->push(3) .push(7) .pop() .push(16) .pop() .push(12) .push(244) .push(9) .pop() .pop() .clear() .printHistoryTo(std::cout); 

Output:

 +----+---+----+ 0 | <- | 3 | <- | +----+---+----+ +----+---+---+----+ 1 | <- | 3 | 7 | <- | +----+---+---+----+ +----+---+----+ 2 | <- | 7 | <- | +----+---+----+ +----+---+----+----+ 3 | <- | 7 | 16 | <- | +----+---+----+----+ +----+----+----+ 4 | <- | 16 | <- | +----+----+----+ +----+----+----+----+ 5 | <- | 16 | 12 | <- | +----+----+----+----+ +----+----+----+-----+----+ 6 | <- | 16 | 12 | 244 | <- | +----+----+----+-----+----+ +----+----+----+-----+---+----+ 7 | <- | 16 | 12 | 244 | 9 | <- | +----+----+----+-----+---+----+ +----+----+-----+---+----+ 8 | <- | 12 | 244 | 9 | <- | +----+----+-----+---+----+ +----+-----+---+----+ 9 | <- | 244 | 9 | <- | +----+-----+---+----+ +----+---------------+----+ 10 | <- | <empty queue> | <- | +----+---------------+----+ 

Trace Algorithms

LCS (Longest Common Sequence)

auto lcs = (new alg_lcs())->setValue( "ABCBDAB", "BDCABA" ).run().printLcsTo(std::cout); 

Output:

+-----------------------------+ | Longest Common Sequence | +-----------------------------+ | - - A B C B D A B | | - 0 0 0 0 0 0 0 0 | | B 0 0 1 1 1 1 1 1 | | D 0 0 1 1 1 2 2 2 | | C 0 0 1 2 2 2 2 2 | | A 0 1 1 2 2 2 3 3 | | B 0 1 2 2 3 3 3 4 | | A 0 1 2 2 3 3 4 4 | +-----------------------------+ | len: 4 | +-----------------------------+ | lcs: BCBA | +-----------------------------+ | lcs: BDAB | +-----------------------------+